1. Perimeters and Areas of Similar Figures 11.3

2. theorem Areas of Similar Polygons If two polygons are similar with a scale factor of a:b then the ratio of their areas is a2:b2 a2:b2

3. trapezoid I ~ trapezoid II ka I kb II theorem

4. example L S hexagon L ~ hexagon S the scale factor is 3:2 Find the ratio of the perimeters Find the ratio of the areas

5. example A rectangular tablecloth is 60 in by 120 in. A rectangular placemat made from the same cloth is 12 in by 24 in. The placemat costs $5. Compare the areas of the placemat and the tablecloth to find a reasonable cost for the tablecloth. scale factorratio of areascost comparison $125

6. example A store sells trampolines that are all regular hexagons. One trampoline has a side length of about 4.5 ft. and an area of about 52.6 ft 2. Find the area of the trampoline whose perimeter is 67.5 ft. 328.75 ft 2 scale factorratio of areasarea comparison