1. 6.4 Special Parallelograms
Brett Solberg AHS ‘11-’12

2. Warm-up 1) Solve for x, y, and z. 2) Solve for x and y
What HW questions do you want to review?
5x – y
2x x - 2

3. Today’s Agenda Quiz Special Parallelograms 1/10 6.5 1/12 Review/Test
Rhombus
Rectangle
1/10 6.5
1/12 Review/Test

4. Quiz
You can use your notes.
Read the directions carefully.

5. Rhombus
A Rhombus is a parallelogram with congruent side lengths.

6. Theorem 6.9
Each diagonal of a rhombus bisects 2 angles.

7. Example 1

8. Theorem 6.10
The diagonals of a rhombus are perpendicular.

9. Example 2

10. Geogebra
Visualizing the theorems

11. Converses
6.9 – If a parallelogram is a rhombus, then each diagonal bisects 2 angles.
6.12 – If a diagonal in a parallelogram bisects 2 angles, then the parallelogram is a rhombus.
6.10 – If a parallelogram is a rhombus, then the diagonals are perpendicular.
6.13 – If the diagonals of a parallelogram are perpendicular, then the parallelogram is a rhombus.

12. Rectangle
A parallelogram with 4 right angles.

13. Rectangle
6.11 If a parallelogram is a rectangle ,then the diagonals are congruent
DF = GE
6.14 If the diagonals of a parallelogram are congruent, then the parallelogram is a rectangle.

14. Example 3
FD = 2x + 4
GE = 6x - 5

15. Homework
6.4 Worksheet and pg 332 # 1-20 even