1. Circle Limit III M.C. Escher Section 6-2 Spi.2.2.B Jim Smith JCHS JCHS

2. Similar figures look alike but one is a smaller version of the other. Like Dr. Evil and Mini-Me. version of the other. Like Dr. Evil and Mini-Me. It wouldn’t make much sense to make a drawing It wouldn’t make much sense to make a drawing of this ship the actual size of the ship.

3. Just like congruent polygons, the corresponding angles in similar polygons must be congruent.

4. AX C D B W Z Y A = 80° B = 30° Z = 170° A = 80° B = 30° Z = 170° W = ___ X = ___ D = ___ W = ___ X = ___ D = ___ 80°30°170°

5. The sides are a little different. They must be PROPORTIONAL. A X C D B W Z Y AB = BC = CD = DA AB = BC = CD = DA WX XY YZ ZW WX XY YZ ZW

6. This means I should be able to multiply each side of the smaller polygon by the same number and get it’s corresponding side on the bigger polygon. 4 4x2 = 8 5 5x2 = 10 2 2x2 = 4 3 3x2 = 6

7. The SCALE FACTOR is the ratio of the corresponding sides of the corresponding sides SMALL BIG BIG SMALL BIG SMALL or

8. What is the scale factor of these polygons? 10 4 X7 Y 8 Z 6 Scale Factor = 104 = 52

9. 4 7 Y Z 10 X 8 6104=52 Use the scale factor to find the other sides 5 6 2 Z = 5z = 12 z = 12 = 2.4 z = 12 = 2.4 5 SF = 5 X 2 7 2x = 35 x = 35 = 17.5 x = 35 = 17.5 2 = 5 8 2 Y 5y = 16 y = 16 = 3.2 y = 16 = 3.2 5 =