1. 6-4 Properties of Rhombuses, Rectangles, and Squares

2. Special Parallelograms
A rhombus is a parallelogram with four congruent sides.
A rectangle is a parallelogram with four right angles.
A square is a parallelogram with four congruent sides and four right angles.

3. Classifying Special Parallelograms
Is parallelogram ABCD a rhombus, a rectangle, or a square? Explain.
Is parallelogram EFGH a rhombus, a rectangle, or a square? Explain.

4. Rhombus Properties
Theorem 6-13: If a parallelogram is a rhombus, then its diagonals are perpendicular. Theorem 6-14: If a parallelogram is a rhombus, then each diagonal bisects a pair of opposite angles.

5. Finding Angle Measures
What are the measures of the numbered angles in rhombus ABCD?

6.  What are the measures of the numbered angles in rhombus PQRS?

7. Rectangle Properties
Theorem 6-15: If a parallelogram is a rectangle, then its diagonals are congruent.

8. Finding Diagonal Length
If SF = 2x + 15 and RB = 5x – 12, what is the length of a diagonal of rectangle RSFB?

9.  If LN = 4x – 17 and MO = 2x + 13, what are the lengths of the diagonals of rectangle LMNO?