1. Today’s Agenda (1/10) Tomorrow: Meet in G121!
1) Check HW/Work on Warm-up
Have your HW on your desk when the bell rings.
2) 7.2 Notes –Similar Polygons
3) HW Time: 7.2 Worksheet (p.15) #’s 1-5

2. 7.2 Notes Similar Polygons
Today’s Objectives:
1. Students will be able to use proportions to identify similar polygons.  
2. Students will be able to solve problems using the properties of similar polygons.

3. Similarity Statements
Vocab!
 Similar Polygons
 Similarity Statements

4. Example 1
a) If ΔABC ~ ΔRST, list all pairs of congruent angles and write a proportion that relates the corresponding sides.

5. Example 1 cont.
b) If ΔGHK ~ ΔPQR, determine which of the following similarity statements is not true. A) HGK  QPR B) C) K  R D) GHK  QPR

6. Vocab!
Scale Factor

7. Example 2
a) David is designing a new menu for the restaurant where he works. Determine whether the size for the new menu is similar to the original menu. If so, write the similarity statement and scale factor. Explain your reasoning.
New Menu:
Original Menu:

8. Example 2 cont.
b) Eliseo is designing a new menu for the restaurant where he works. Determine whether the size for the new menu is similar to the original menu. If so, write the similarity statement and scale factor. Explain your reasoning.
Original Menu:
New Menu:

9. Example 3
a) The two polygons are similar. Find the values of x and y.

10. Example 3 cont.
b) The two polygons are similar. Solve for a and b .

11. Vocab
Perimeters of Similar
Polygons

12. Example 4
a) If ABCDE ~ RSTUV, find the scale factor of ABCDE to RSTUV and the perimeter of each polygon.

13. Example 4 cont.
b) If LMNOP ~ VWXYZ, find the perimeter of each polygon.

14. Summary Quadrilateral ABCDEFGH. Find the following:
Their scale factor
The values of x, y, and z
The perimeter of the two quadrilaterals
The ratio of the perimeters

15. Summary Quadrilateral IJKLMNOP. Find the following:
5. What is the scale factor of quadrilateral IJKL to quadrilateral MNOP?
6. Find m∠ I.
7. Find m∠ L.
8. Find NO.
9. Find IJ.