2.  Rhombus – a parallelogram with four congruent sides.  Rectangle – a parallelogram with four right angles.

3.  Theorem 6-9: Each diagonal of a rhombus bisects two angles of the rhombus.  Theorem 6-10: The diagonals of a rhombus are perpendicular.

4.  Theorem 6.11: The diagonals of a rectangle are congruent.

5.  Find the measures of the numbered angles in the rhombus. 2 2 43 1 78°

6.  One diagonal of a rectangle has length 8x + 2. The other diagonal has length 5x + 11. Find the length of each diagonal.

7.  Page 315 # 1-15

8.  Theorem 6.12: If one diagonal of a parallelogram bisects two angles of the parallelogram, then the parallelogram is a rhombus.  Theorem 6.13: If the diagonals of a parallelogram are perpendicular, then the parallelogram is a rhombus.  Theorem 6.14: If the diagonals of a parallelogram are congruent, then the parallelogram is a rectangle.

9.  A diagonal of a parallelogram bisects two angles of the parallelogram. Is it possible for the parallelogram to have sides of lengths 5, 6, 5, and 6? Explain.

10.  The diagonals of ABCD are perpendicular. AB = 16 cm and BC = 8 cm. Can ABCD be a parallelogram? Explain.

11.  Builders use properties of diagonals to “square up” rectangular shapes like building frames and playing field boundaries.  How could you use diagonals to locate the four corners of a rectangular patio?  How could you use diagonals to locate the four corners of a square patio?  How could you use diagonals to locate the for corners of a patio shaped like a rhombus?

12.  Page 315 # 16-21, 45-53