1. Warm UP
Given J(2, 2), K(-3, 2), L(-6, 6), and M(-1, 6) form a parallelogram.
Create a coordinate proof to justify what kind of parallelogram it is.

2. Objective
SWBAT identify properties of kites and trapezoids in order to find angle and length measurements.

3. Homework
P. 432: # 2 – 10, 14 – 20, 23 – 32

4. Coordinate Plane Draw a coordinate plane. Plot the line x = 2.
Draw a scalene triangle so that the long side lies along the line x = 2.

5. Coordinate Plane Reflect the triangle over the line x = 2.
What have you made?

6. Kite
From your chart, what properties did we say the kite had?

7. Note: These are in one direction only!
Kite
Note: These are in one direction only!

8. Think About It
If the theorems only work if something is already known to be a kite, how will we know if we have a kite?

9. Kite Example In kite ABCD, mDAB = 54°, and mCDF = 52°. Find mBCD.
Find mABC.

10. Kite Example
Lucy is making a kite for the school fair. She uses two dowels as diagonals to keep the kite open. Using the measurements in the picture, how long must the dowel for KL be?

11. Classwork
Kite Practice
Show all work

12. Quadrilateral Joke
What do you get when you cross a triangle with a guillotine?
A trapezoid

13. Trapezoid A quadrilateral with one pair of parallel sides.
Note some of the similar vocabulary.

14. Trapezoid On its own, the trapezoid hasn’t got much to offer.
But the isosceles trapezoid does.

15. Isosceles Trapezoid

16. Caution
The last theorem is a biconditional and it only works if the shape is already a trapezoid.

17. Example
Find mB.
Find mD.
Find mA.

18. Example
KB = 21.9 and MF = 32.7.
Find KJ.
Find FB.

19. Converse Example
Find the value of a so that PQRS is isosceles.

20. Converse Example
Given AD = 12x – 11 and BC = 9x – 2. Find the value of x so that ABCD is isosceles.

21. Classwork
Practice – Properties of Trapezoids
Show ALL work

22. Summary
Why is the isosceles trapezoid the more appreciated trapezoid?

23. Homework
P. 432: # 2 – 10, 14 – 20, 23 – 32