20 terms

plane

a flat surface of points that goes on forever in all directions

complementary angles

two angles whose sum measures 90 degrees

line segment

an infinite number of points that has two distinct end points

supplementary

two angles whose sum measures 180 degrees

ray

an infinite set of points that starts at a point and goes on forever

obtuse angle

an angle whose measure is greater than 90 degrees and less than 180

bisect

to cut into two congruent parts

line

an infinite number of points that goes on forever in both directions

acute angle

an angle whose measure is greater than 0 degrees and less than 90 degrees

right angle

an angle formed by two perpendicular lines, the measure of which is 90 degrees

straight angle

an angle whose measure is 180 degrees

vertex

the point of intersection of the two rays that form the sides of the angle

angle

a geometric figure formed by two rays that have a common endpoint

collinear

points that lie on the same line

coplanar

any three or more points that lie in the same plane

perpendicular

lines that intersect to form right angles

congruent

having the same size and shape

point

a location in space (it has no dimensions)

midpoint

The point that divides a segment into two congruent segments.

intersect

to meet at a point