6

Perpendicular Bisector Theorem

If a point is on the perpendicular bisector of a segment, then it is equidistant from the endpoints of the segment.

Converse of the Perpendicular Bisector Theorem

If a point is equidistant from the endpoints of a segment, then it is on the perpendicular bisector of the segment.

Concurrent Lines

Three or more lines that intersect at a single point.

Incenter of a Triangle

The point where the angle bisectors of a triangle intersect, which is equidistant from all sides of the triangle.

Reflexive Property of Congruence

Any geometric figure is congruent to itself.

Triangle Midsegment Theorem

The segment connecting the midpoints of two sides of a triangle is parallel to the third side and half as long.

Indirect Proof

A proof that assumes the opposite of what you are trying to prove to show that a contradiction arises.

Triangle Inequality Theorem

In any triangle, the sum of the lengths of any two sides must be greater than the length of the third side.

Single-Ride Theorem

In any triangle, the longest side is opposite the largest angle.

Converse of the Single-Ride Theorem

If one side of a triangle is longer than another side, then the angle opposite the longer side is larger than the angle opposite the shorter side.