26 terms

# Geometry Vocabulary

#### Terms in this set (...)

Collinear
Points that lie on the same line
Linear Pair
A pair of adjacent angles whose noncommon sides are opposite rays.
Supplementary angles
Two angles whose sum is 180 degrees
Complementary angles
Two angles whose sum is 90 degrees
Vertical Angles
A pair of opposite congruent angles formed by intersecting lines
Angle addition postulate
If P is in the interior of <RST, then m<RSP + m<PST = m<RST
Segment addition postulate
If B is between A and C, then AB + BC = AC
Congruent
Having the same size and shape
Angle bisector
a ray that divides an angle into two congruent angles
Segment bisector
a segment, ray, line, or plane that intersects a segment at its midpoint
Midpoint
A point that divides a segment into two congruent segments
postulate
something accepted as true without proof; an axiom
theorem
A mathematical statement which we can prove to be true
Line segment
A part of a line with two endpoints
Line
A straight path that has no thickness and extends forever.
Plane
A flat surface that has no thickness and extends forever.
Distance
the length between any two points in the absolute value of the difference of the coordinates
Distance Formula
d = √[( x₂ - x₁)² + (y₂ - y₁)²]
Midpoint Formula
The formula for a halfway point between two coordinates.
Pythagorean Theorem
The sum of the squares of the legs of a right triangle is equal to the square of the hypotenuse.
adjacent angles
Angles that have a common side and a common vertex (corner point).
Angle
A figure formed by two rays with a common endpoint
acute angle
an angle that measures more than 0 degrees, but less than 90 degrees
obtuse angle
An angle that measures more than 90 degrees but less than 180 degrees
right angle
an angle that measures 90 degrees
straight angle
an angle that measures 180 degrees