Vocabulary

- an angle whose measure is greater than 0 but less than 90 degrees; see obtuse angle

- 2 nonstraight and nonzero angles that have a common side in the interior of the angle formed by the noncommon sides

- a sequence of steps leading to a desired end

- exterior angles on alternate sides of the transversal (not on the same parallel line)

- ditto as above, only with interior angles

- height

- the length of a segment whose endpoints are the vertex and a point on the plane of the base that is perpendicular to the plane of the base

- the distance between the planes of the bases

- the distance between the bases of a trapeziod

- the perpendicular segment from a vertex to the line containing the opposite side of a triangle

- not stable; changing

- see coordinate geometry

- the union of 2 rays that have the same endpoint; measured in degrees or radians (trig.); the five types of angles are zero, acute, right, obtuse, and straight

- a ray that is in the interior of an angle and forms two equal angles with the sides of that angle

- the smallest of the angles formed when a line intersects a plane

- one of the two rays forming an angle

- the 'if' part of a conditional; represented by p; aka hypothesis, given, problem; see consequent

- the amount of space taken up in a plane by a figure

- the distance between an arc's endpoints along the path of the circle

- the area of figure F

- a computer program that lets you build constructions

- the line containing the vertex of a conic solid and the center of the base

- the side of an isoscoles triangle whose endpoints are the vertices of the base angles

- the angle opposite one of the equilateral sides in an isoscoles triangle

- consecutive angles that share a base of a trapezoid

- the planar region that forms the widest point of a conic solid; often labeled as the 'bottom' of the conic solid, it determines the exact shape of the conic solid

- the original region and its translation image

- the parallel sides of a trapezoid

- a conditional and its converse where the converse is also true; uses the words if and only if; written pq

- see reflection symmetry

- see angle bisector

- any plane, point or two-dimensional figure containing the the midpoint of the segment and no other points on that segment

- a surface made up of rectangles; a rectangular parallelpided

- see volume

- a coordinate plane

- the point that all points in the circle are equidistant from

- the point where the two intersecting lines of a rotation meet

- the mean of the coordinates of points in a figure, whether one, two, or three-dimensional

- an angle whose vertex is the center of the circle

- a segment whose endpoints are on a circle

- the set of points on a plane at a certain distance (radius) from a certain point (center); a polygon with infinite sides

- when on a search, circling back to a previous place visited (definition, web site, etc.), usually unhelpful or redundant

- the perimeter of a circle

- in orientation, the direction in which the points are named when, if traveling along the line, the interior of the polygon is on the right (got all that?); see counterclockwise

- lines that are identical (one and the same)

- in the same line

- a drawing tool used to draw circles at different radii

- 2 angles whose measures, when added together, equal 90 degrees; see supplementary angles

- The composite of a first transformation S and a second transformation T is the transformation mapping a point P onto T(S(P)). When written T₂ #PRIVATE "TYPE=PICT;ALT=degree symbol"T₁, do T₁ first; see translation, rotation, glide reflection, similarity transformation

- see nonconvex

- circles that share the same center, but have different radii

- a statement that tells if one thing happens, another will follow; written as pq; see antecedent, consequent, converse, inverse, contrapositive

- the surface of a conic solid whose base is a circle; see right cone

- see isometry

- equilateral, equal, exactly the same (size, shape, etc.)

- two figures where one is the image of the other under a reflection or composite of reflections;

- plane section of a cone

- the set of points between a point (the vertex) and a non-coplanar region (the base), including the point and the region; see cone, pyramid, regular pyramid, right cone

- an educated guess or opinion; a hypothesis

- sides of a polygon that share an endpoint

- endpoints of a single side of a polygon

- the 'then' part of a conditional; represented by q; aka conclusion, prove, answer

- the term that has no variable in an equation; example: C

- a precise way of drawing which allows only 2 tools: the straightedge and the compass

- a size change where k is less than 1

- a type of conditional; if not q, then not p; written ~q~p; see inverse

- a reversed conditional; if a conditional is pq, than its converse is qp

- a set of points in which all segments connecting points of the set lie entirely in the set; There are three things one can do to see if a figure is convex - look for "dents", extend the segments (they shouldn't enter the figure), and connect any two points within the figure with a segment (if any part of the segment lies outside the figure, it's concave); see nonconvex set

- a number that identifies (or helps to identify) a point on a number line (or on a plane, or in space)

- the study of geometrically representing ordered pairs of numbers

- a plane in which every point is identified with exactly 1 number and vice versa; a two-dimensional graph

- a line on which every point is identified with exactly 1 number and vice versa; a one-dimensional graph. The distance between 2 parts on a coordinatized line is the absolute value of the difference of their coordinates.

- within the same plane

- a theorem that is easily proved from the first

- any pair of angles in similar locations with respect to a transversal

- two angles that have the same terminal side

- in orientation, the direction in which points are named when, if travelling on the line, the interior of the figure is on the left side; see clockwise

- a situation in a conditional for which the antecedent is true, but the conditional is false; aka contradiction

- the set of points between a region and its translation in space, including the region and its image

- the surface of a cylindric solid whose base is a circle; see right cylinder

- the union of the bases and the lateral surface

- a ten-sided polygon

- unit used to measure angles

- the line that contains the shortest path between two points

- a segment in a polygon whose endpoints are 2 nonconsecutive vertices

- the segment whose endpoints are points on a circle (or sphere) that contains the center of the circle as its midpoint; the length of that segment

- see size change

- see size change

- the width, length, and height of a plane or space figure

- the way a number goes - positive or negative

- the compass direction in which a translation goes (duh)

- a line made of dots with space inbetween their centers

- the distance between points A and B is written as AB

- the length of a perpendicular segment between them

- a twelve-sided polygon

- a description of a point in which the point has a definite size

- a twelve-sided polygon

- a freehand picture using any tool; see construction

- a segment that helps to make up a face

- see null set

- the common vertices of the equilateral sides of a kite

- a nine-sided polygon

- having angles of the same measure

- the same distance from something

- equal in length

- a triangle whose sides are equal in length

- a node that has an even number of arcs

- one or the other, but not both

- a conditional that uses the word 'same'

- a size change where k is greater than 1

- angles outside of two lines cut by a transversal; see interior angles

- the nonconvex set formed by an angle that measures less than 180 degrees; see interior of an angle

- in the proportion , a and d; see means

- a polygonal region of a surface

- hierarchy; tower or pyramid of power or importance

- a set of points

- an isoscoles right triangle

- a region used in a tesselation

- the number g such that for two numbers a and b,

- information assumed to be true in a proof

- a type of composite transformation where a figure is reflected and then translated in a parallel direction

- if n is an even number greater than 2, then there are always 2 prime numbers whose sum is n

- the tilt of a real-life object in relation to the horizontal, often used to determine how steep a hill is

- the mathematics of complicated networks

- the circle formed by the intersection of a sphere and the plane that contains its center and that divides the sphere into two hemispheres; see small circle

- a tesselation of congruent squares sometimes used to measure distance

- two times the product divided by the sum of the two numbers

- half of a sphere

- a seven-sided polygon

- a six-sided polygon

- broken lines used to signify lines that normally wouldn't be seen in a drawing

- a chart that shows varying levels of importance

- the side opposite the right angle in a right triangle

- a 20-sided solid; each side is in the shape of a triangle

- a reflection where the preimage and the image are the same; see reflection symmetry

- a size change where k equals 1

- if and only if; see biconditional

- see conditional

- the reflection of the preimage

- a subset that includes the entire parent set; see proper subset

- the angle made by two sides of a polygon

- the side between two angles in a polygon

- one or the other, or both; and/or

- uncountable

- the side that the measurement of an angle starts from; see terminal side

- a situation where the statement is true

- angles between two lines cut by a transversal; see exterior angles

- the convex set formed by an angle that measures less than 180 degrees; see exterior of an angle

- the set of points whose distance from the center of the circle is less than that of the radius

- planes that share a line

- the set of elements which are in both A and B;

- a form of conditional; if not p, then not q;

- decimal number that never ends, never repeats (Ex: pi)

- region whose boundary is not the union of circular arcs or segments

- a transformation that keeps the same size and shape of a figure but moves it to a new location; see reflection, rotation, translation, glide reflection

- a trapezoid that has a pair of equiangular base angles

- a triangle with two sides of equal length

- a quadrilateral that has two distinct pairs of consecutive equilateral sides

- lateral area

- the area of the lateral surface of a solid

- a segment whose endpoints are corresponding points of a cylindric solid's bases, or whose endpoints are the vertex of a conic solid and a vertex of its base

- the faces of the lateral surface of a prism, or a face of a pyramid that is not a base

- the surface not included in the base(s)

- points in the coordinate plane with integer coordinates

- a side of a right triangle that include the 90 degree angle

- the actual area of a region

- a two-dimensional object that has no endpoints and continues on forever in a plane; formed of infinite points; the 3 orientations that lines may have are horizontal vertical, oblique, and skew lines; written

- Ax + By + C = 0

- 2 supplementary adjacent angles whose noncommon sides form a line

- the term with a variable, but no exponent in an equation; example: By in a linear equation

- numbers on the left side of a computer screen that tell the computer in what order to do instructions in a computer programming language such as BASIC

- the line that is reflected over in a reflection

- a line perpendicular to every line in the plane that it intersects (or any one of them)

- lines from an eye to what it sees that show perspective and what size to draw it

- one of the four main description of a point

- the set that satisfies a given condition

- the value of a number; its distance from the origin

- the amount of rotation in degrees

- the distance between any point and its image

- an arc whose endpoints form an angle over 180 degrees with the center of the circle; written - the extra letter is used to distinguish it from a minor arc; see minor arc

- making a transformation

- arrangement of pixels

- average

- a version of a conditional that defines a term, where the term is in the antecedent; see sufficient condition

- in the proportion , b and c; see extremes

- the amount of openness in an angle

- the segment connecting the vertex of an angle in a triangle to the midpoint of the side opposite it

- the point M of where AM = AB

- an arc whose endpoints form an angle less than 180 degrees with the center of the circle;

- a 2-D figure that can be folded on its segments or curved on its boundaries to form a 3-D figure; see article here

- a group of nodes and arcs

- a polygon with n sides

- a description of a point in a network where it is possible for two different segments to share the same endpoints

- a nine-sided polygon

- a set of points in which not all segments connecting points of the set lie entirely in the set; synonym: concave; see convex set

- solid geometry

- the side of a triangle that is not included by 2 given angles

- regions that don't share interior points

- a three-dimensional drawing that doesn't use perspective

- a set with nothing in it

- a coordinatized line

- a non-right prism or cylinder

- a line that has a definite slope not equal to zero

- an angle whose measure is greater than 90 but less than 180 degrees; see acute angle

- an eight-sided polygon

- a node with an odd number of arcs

- having length, but no width; examples: a line, a ray, a segment

- faces that lie in parallel planes

- two rays with a common endpoint that form a line

- the two numbers that (called coordinates) are used to identify a point in a plane; written (x, y)

- the three numbers (called coordinates) that are used to identify a point in space; written (x, y, z)

- in an image change, the direction in which the points named go (i.e., how A's position relates to B's and B's relates to C's); either clockwise or counterclockwise for figures

- triangles that share a side or angle

- two or more coplanar lines that have no points in common or are identical (eg, the same line)

- a quadrilateral with both pairs of opposite sides parallel

- a prism whose opposite faces are all parallelograms and congruent (in pairs)

- planes that have no points in common

- a 15-sided polygon

- a five-sided polygon

- the sum of the lengths of the sides of the polygon

- the bisector of a segment perpendicular to it

- 2 segments, rays, or lines that form a 90 degree angle

- planes in which any two intersecting lines, one in each plane, form a right angle

- feeling of depth

- a drawing in which, in order to show perspective, oblique parallel lines will meet

- written π ( for those of you who can't read math tags yet); the ratio C/D where C is the circumference and D is the diameter of a circle; 3.14159265359

- small dot of color that makes up computer and TV screens

- a two-dimensional group of points that goes on infinitely in all directions; made up of infinite lines

- a set of points that are on a plane

- the study of two-dimensional figures in a plane

- the intersection of a figure with a plane

- a zero-dimensional figure; while usually left undefined, has four main representions - the dot, the node, the location, and the ordered pair of numbers

- the positivity or negativity of a variable; its direction

- a union of 3 or more segments where each segment intersects 2 other segments, one at each endpoint; "many sided"; see reflex polygon

- the union of a polygon and its interior

- a three-dimensional surface which is the union of polygonal regions and has no holes

- a statement assumed to be true without proof; see theorem

- the original object that is reflected

- the surface of a cylindric solid whose base is a polygon; see right prism, parallelpiped, box

- a sequence of justified conclusions used to prove the validity of an if-then statement

- a subset that doesn't include everything in its parent set; see improper subset

- a statement that two ratios are equal

- one of four numbers that form a true proportion

- a tool used to measure angles

- the goal of a proof

- the surface of a conic solid whose base is a polygon; see regular pyramid

- a set of three numbers that can be side lengths of a right triangle

- "quod erat demonstrandum" (Latin) This stems from medieval translators' habitual tendency of translating the Greek for "this was to be demonstrated" to the Latin phrase above. This appeared originally at the end of many of Euclid's propositions, signifying that he had proved what he set out to prove.

- "quod erat faciendum" is the latin for "which was to be done" It appears in Latin translations of Euclid's works signifying that he had demonstrated what he had set out to demonstrated.

- a four-sided polygon; see quadrilateral

- Ax² + By + C = 0

- the term Ax² in a quadratic equation

- a four-sided polygon; see rhombus, parallelogram, square, rectangle, trapezoid, isoscoles trapezoid, kite

- rotation

- radius

- plural form of radius

- the segment whose endpoints are any point on a circle or sphere and its center; the length of that segment

- a ratio where the quantities are of different kinds; example: 60 miles per hour

- a quotient of 2 numbers

- the ratio of the length of an image to the length of the preimage

- a one-dimensional figure that consists of one endpoint A, one point B, all of the points on , and all points for which B is between them and A;

- a quadrilateral whose angles are all right angles

- the union of a box and its interior

- the angle of less than 360 degrees that corresponds to an angle of over 360 degrees; In order to get the reference angle, you must subtract 360 degrees from the given angle until there is less than 360 degrees left.

- to change a conjecture slightly so that it is true

- see line of reflection

- For a point A not on the reflecting line, its reflection image is the point B where the reflecting line is the perpendicular bisector of . For a point A on the reflecting line, its reflection image is itself.

- the set of all of the reflection images of points in the figure

- r_m(ABC), which stands for the reflection over line m of figure ABC

- a figure that shows reflection symmetry

- a characteristic of a figure in which there is a reflection line where its reflection is itself

- a polygon for which 2 or more of its sides intersect each other

- the union of a figure and its interior

- a convex polygon whose angles and sides are all congruent

- a pyramid whose base is a regular polygon and whose vertex forms a segment with the center of the polygon perpendicular to its plane

- the density of pixels in a picture

- a parallelogram with four equilateral sides

- an angle whose measure is 90 degrees

- a cone whose axis is perpendicular to the plane containing its base

- a cylinder whose direction of sliding is perpendicular to the plane of the base