Angle and Segment Proofs

A midpoint is a point that divides a segment into two equal parts.

For any segment or angle, it is congruent to itself, i.e., $$\text{If } AB \text{ is a segment, then } AB \text{ is congruent to } AB$$ .

If two values are equal, one can be substituted for the other in any expression.

Two figures are congruent if they have the same shape and size.

Two angles are complementary if the sum of their measures is $$90^\text{o}$$ .

A right angle is an angle that measures exactly $$90^\text{o}$$ .

If point B is between points A and C, then $$AB + BC = AC$$ .

Two angles are supplementary if the sum of their measures is $$180^\text{o}$$ .

If $$\triangle ABC \text{ is congruent to } \triangle DEF$$ , then $$\triangle DEF \text{ is congruent to } \triangle ABC$$ .

A segment bisector is a point, ray, line, or plane that intersects a segment at its midpoint.