Notes for March 25th, 2008

Definition- Rectangle
A rectangle is a parallelogram with four right angles.

PROPERTIES
1. Opposite sides are congruent and parallel.
2. Opposite angles are congruent.
3. Consecutive angles are supplementary.
4. Diagonals bisect each other and are congruent.
5. All four angles are right angles.

Theorems, Postulates, & definitions.

Theorem 8-13: If a parallelogram is a rectangles the diagonals are congruent.
Note: If one angle of a parallelogram is a right angle then the parallelogram is a rectangle.
The Housebuilder Theorem 8-14: If the diagonals of a parallelogram are congruent then the parallelogram are congruent then the parallelogram is a rectangle.
Rhombi and Squares
Theorem 8-15: The diagonals of a rhombus is perpendicular.
Theorem 8-16: If the diagonals of a parallelogram are perpendicular then the parallelogram is a rhombus.