Geometry Concepts and Theorems

Front

Perpendicular bisector

Back

A bisector of a segment that is perpendicular to the segment.

Front

Median

Back

In a triangle, a segment that joins a vertex of the triangle and the midpoint of the opposite side.

Front

Altitude

Back

Has one endpoint at a vertex of a triangle and the other on the line that contains the side opposite that vertex so that the segment is perpendicular to this line.

Front

Angle bisector

Back

The ray, QS, is the bisector of angle PQR if S is the interior of the angle and angle PQS is congruent to angle RQS.

Front

Theorem 5-9

Back

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

Front

Theorem 5-10

Back

If one angle of a triangle has a greater measure than another angle, then the side opposite the greater angle is longer than the side opposite the lesser angle.

Front

Theorem 5-11

Back

The perpendicular segment from a point to a line is the shortest segment from the point to the line.

Front

Corollary 5-1

Back

The perpendicular segment from a point to a plane is the shortest segment from the point to the plane.

Front

Theorem 5-12 (Triangle Inequality Theorem)

Back

The sum of the lengths of any two sides of a triangle is greater than the length of the third side.

Front

Quadrilaterals

Back

A four-sided polygon.