12 terms

midpoint

If a point is a midpoint then it divides the segment into two congruent segments.

angle bisector

if a ray bisects an angle then it divides the angle into two congruent angles.

trisect

if two points trisect a segment then they divide the segment into three congruent segments.

angle trisector

if two rays trisect an angle then they divide the angle into three congruent angles.

congruence

if two angles (or segments) have the same measure then they are congruent.

perpendicular

if two lines are perpendicular then they form a right angle.

complementary

if two angles sum to a right angle then they are complementary

acute angle

if an angle measures between 0 degrees and 90 degrees then it is an acute angle.

obtuse angle

if an angle measures between 90 degrees and 180 degrees then it is an obtuse angle.

supplementary

if two angles sum to a straight angle then they are supplementary.

right angle

if an angle measures 90 degrees then it is a right angle.

straight angle

if an angle measures 180 degrees then it is a straight angle.