# Mathematics

## 77 terms · Chapter One Vocabulary -- Robinson IB Program 2011-2012 School Year

### line

a straight continuous arrangement of infinitely many points

### plane

has length and width but no thickness

### definition

a statement that clarifies or explains the meaning of a word or phrase

points on a line

### coplanar

points on the same plane

### endpoints

two points that define a segment

### line segment

consists of the endpoints and all the oints in between that are collinear with the two points

### midpoint

the point on the segment that is the same distance from both end points

### bisects

divides the segment into two congruent segments

### angle

formed by two rays that share a common endpoint

### vertex

common endpoint of the two rays

two rays

### measure of an angle

the smallest amount of rotation about the vertex from ray to the other

### `degrees

measurement of an angle; any value between 0 degrees and 180 degrees

### protractor

a geometry tool to measure an angle

### congruent angles

two angles that have the same measure

### angle bisector

a ray that contains the vertex and divides the angle into two congruent lines

### incoming angle

formed by the cushion and the path of the ball approaching the cushion

### outgoing angle

formed by the cushion and the path of the ball leaving the cushion

### counterexample

try to create a figure that fits your definition but isn't what you're trying to say

### skew

two lines that do not intersect are non-coplanar lines "skew lines"

### acute angle

an angle that measure less than 90 degrees

### obtuse angle

an angle that measures more than 90 degress

### linear pair of vertical angles

two angles that are adjacent and supplementary

### pair of vertical angles

two lines intersecting to form an angle that only share a vertex

### pari of complementary angles

two angles the measures of which sum to 90 degrees

### pair of supplementary angles

a pair of angles the measures of which sum to 180 degrees

### polygon

a closed figure in a plane formed by connecting line segments endpoint to endpoint with each segment intersecting exactly two others

### side

a line segment forming part of the perimeter of a plane figure

### vertex

each endpoint where sides meet is called a vertex

### diagonal

line segment that connects two nonconsecutive vertices

### convex figures

no diagonals on the outside

### concave figure

at least on diagonal is on the outside

### equilateral polygon

all sides have equal length

### equilangular polygon

all angles have the same measure

### regular polygon

both equilateral and equilangular

### assume

to accept as true without facts or proof

### right triangle

a triangle with one angle that has a measure of 90 degrees

### acute triangle

a triangle where all the internal angles are less than 90 degrees

### obtuse triangle

a triangle where one of the internal angles has a measure greater than 90 degrees but less than 180 degrees

### Just seeing if you

ARE PAYING ATTENTION

### equilateral triangle

a triangle with three internal angles with the same measure, that measure being 60 degrees, and with three sides of equal length

### isosceles triangle

a triangle with at least two sides with two equal lengths and two angles with equal measures

### trapezoid

a quadrilateral with at least one pair of parallel sides

### kite

a quadrilateral with four sides that can be grouped into two pairs of sides that equal lengths, with sides of equal length being adjacent to each other (compare to parallelogram)

### parallelogram

a quadrilateral with opposite sides being of equal length

### rhombus

a parallelogram in which all sides are of equal length

### vertex angle

the angle between two sides of equal length

### base

the opposite of the vertex angle

### base angles

two angles opposite the two sides of equal length

### rectangle

all interior angles have a measure of 90 degrees

### square

a regular quadrilateral with four equal sides and four internal angles that measure 90 degrees

### circle

the set of all points in a plane at a given distance from a given point

a segment from the center of a circle to a point on the circumference of the circle

### diameter

a line segment containing the center of the circle and the endpoints of which are on the circumference of the circle

### arc of a circle

two points on the circle and the unbroken part of the circle between the two points

### endpoints

two points on the arc

### semicircle

an arc of a circle whose endpoints are the endpoints of a diameter

### minor arc

an arc of a circle that is smaller than a semicircle

### major arc

an arc of a circle that is larger than a semicircle

### arc measure

the measure of the arc

### centrla angle

the angle with its vertex at the center of the circle

### chord

a line segment whose enSpoints both lie on the circumference D

### diameter

any straight line segment that passes through the center & whose endpoints are on the circle

### tangent

a straight line that touches the outside curve of the circle

### locus

the set of points that satisfy or are determined by specific conditions

### space

the set of all points

### isometric drawing

a two-dimensional drawing of a rectangular prism

### pyramid

the base is a triangle or square and the sides are triangles that meet at a common point

### cylinder

two circular bases with curved sides

### prism

a shape whose bases are the same size and each side is a parallelogram

### conew

circular base with sides that are flat meeting up top

### sphere

perfectly round, three dimensional
[The set of all points in space that are equidistant from a given point]

### hemisphere

a half of a sphere

side bisector

### altitude

line segment perpendicular to the base, creates a 90 degree angle

### perpendicular bisector

cuts base in half and is at 90 degree angle to base