Geometry-Chpt 6

Polygon

A plain figure that is formed by three or more segments called sides. Each side intersects two other sides at each of its endpoints

Parallelogram

A quadrilateral with both pairs of opposite sides parallel.

Diagonal

A segment that joins two nonconsecutive vertices of a polygon.

Base angles

A trapezoid has two pairs of base angles.

Isosceles trapezoid

A trapezoid where the legs are congruent.

Vertex

Each endpoint of the polygon

Octagon

Eight sided polygon

Pentagon

Five sided polygon

Quadrilateral

Four sided polygon

Square Corollary

If a quadrilateral has four congruent sides and four right angles, then it is a square.

Rhombus Corollary

If a quadrilateral has four congruent sides, then it is a rhombus.

Rectangle Corollary

If a quadrilateral has four right angles, then it is a rectangle.

Parallelogram Theorem 6.4

If a quadrilateral is a parallelogram, then its consecutive angles are supplementary.

Parallelogram Theorem 6.5

If a quadrilateral is a parallelogram, then its diagonals bisect each other.

Parallelogram Theorem 6.3

If a quadrilateral is a parallelogram, then its opposite angles are congruent.

Parallelogram Theorem 6.2

If a quadrilateral is a parallelogram, then its opposite sides are congruent.

Parallelogram Theorem 6.8

If an angle of a quadrilateral is supplementary to both of its consecutive angles, then the quadrilateral is a parallelogram.

Parallelogram Theorem 6.7

If both pairs of opposite angles of a quadrilateral are congruent, then the quadrilateral is a parallelogram.

Parallelogram Theorem 6.6

If both pairs of opposite sides of a quadrilateral are congruent, then the quadrilateral is a parallelogram.

Parallelogram Theorem 6.9

If the diagonals of a quadrilateral bisect each other, then the quadrilateral is a parallelogram.

Sides

Intersects exactly two other sides at each of its endpoints.

square

Is a parallelogram with four congruent sides and four right angles.

rhombus

Is a parallelogram with four congruent sides.

rectangle

Is a parallelogram with four right angles.

Trapezoid

Is a quadrilateral with exactly one pair of parallel sides.

Heptagon

Seven sided polygon

Hexagon

Six sided polygon

Rectangle Theorem 6.11

The diagonals of a rectangle are congruent.

Rhombus Theorem 6.10

The diagonals of a rhombus are perpendicular.

Legs

The non parallel sides are the legs.

Bases

The parallel sides of the trapezoid.

Quadrilateral interior angles theorem

The sum of the measures of the interior angles of a quadrilateral is 360°

Triangle

Three sided polygon