13 terms

Polygon Angle-Sum Theorem

The sum of the measures of the interior angles of an n-gon is (n-2)*180.

Equilateral Polygon

A polygon with all sides congruent.

Opposite sides

The two sides that do not share a vertex in a quadrilateral.

Parallelogram

A quadrilateral with two pairs of opposite sides parallel.

Opposite Angles

The two angles that do not share a side in a quadrilateral.

Equiangular Polygon

A polygon with all angles congruent.

Consecutive Angles

Angles of a polygon that share a side.

Regular Polygon

A polygon that is both equilateral and equiangular.

Polygon Exterior Angle-Sum Theorem

The sum of the measures of the exterior angles of a polygon, one at each vertex, is 360 degrees.

Corollary to the Polygon Angle-Sum Theorem

The measure of each interior angle of a regular n-gon is [(n-2)*180]/n

Parallelogram

Quadrilateral with both pairs of opposite sides parallel

Properties of parallelograms

1) both pairs of opposite angles congruent

2) both pairs of opposite sides congruent

3) diagonals bisect each other

4) consecutive angles are supplementary

5) both pairs of opposite sides are parallel

2) both pairs of opposite sides congruent

3) diagonals bisect each other

4) consecutive angles are supplementary

5) both pairs of opposite sides are parallel

Ways to prove a quadrilateral is a parallelogram

1) both pairs of opposite sides are congruent

2) both pairs of opposite angles are congruent

3) one pair of opposite sides is both congruent and parallel

4) consecutive angles are supplementary

5) diagonals bisect each other

6) both pairs of opposite sides are parallel

2) both pairs of opposite angles are congruent

3) one pair of opposite sides is both congruent and parallel

4) consecutive angles are supplementary

5) diagonals bisect each other

6) both pairs of opposite sides are parallel