1. Cole earned a total of $12 by selling 16 cups of lemonade. How many cups of lemonade does Cole need to sell in all to earn $15? Use a ratio table or set up a proportion to solve. 2. Mary received 4 votes for every vote that Jane received people voted. How many votes did Jane receive? Use a ratio table to solve 3. The distance between Philadelphia and San Francisco is 2,950 miles. You look on a map and see the scale is 1 inch : 100 miles. What is the distance between the two cities on the map? Bell Work 20 cups of lemonade 300 votes 29.5 inches

Two objects are similar if they are the same shape but different sizes. Similar Polygons

Example: Is the pair of polygons similar? Explain your answer. 5 m 8 m 10 m 13 m OR 5(13) = 10(8) 65 = 80 NO 5(13) = 8(10) 65 = 80 NO

Example: Is the pair of polygons similar? Explain your answer. 4 yd3 yd 6 yd 4.5 yd OR 4(4.5) = 6(3) 18 = 18 YES 4(4.5) = 6(3) 18 = 18 YES

15 ft9 ft 21 ft 12 ft Yes No Are the polygons similar? You must be able to justify your answer. (Shapes not drawn to scale.)

10 m 8 m 2.5 m 2 m Yes No Are the polygons similar? You must be able to justify your answer. (Shapes not drawn to scale.)

15 yd 6 yd 15 yd 37.5 yd Yes No Are the polygons similar? You must be able to justify your answer. (Shapes not drawn to scale.)

Example: Find the value of x in the pair of similar polygons. 15 cm x 6 cm 8 cm 10 cm OR 15(10) = 6x 150 = 6x 25 cm = x 15(10) = 6x 150 = 6x 25 cm = x

You try: Find the value of y in the pair of similar polygons. y 15 in 5 in 7.5 in 15(5) = 7.5x 75 = 7.5x 10 in = x 15(5) = 7.5x 75 = 7.5x 10 in = x Or

25 ft 18 ft 17.5 ft w Find the measure of the missing value in the pair of similar polygons. (Shapes not drawn to scale.) 12.6 ft A B C D 18ft 450ft.07 ft

17 m 4.25 m 4 mx Find the measure of the missing value in the pair of similar polygons. (Shapes not drawn to scale.) 16m 68ft A B C D 16.25m 18.06ft

11 mm38.5 mm 6 mm y Find the measure of the missing value in the pair of similar polygons. (Shapes not drawn to scale.) 21 mm 33.5mm A B C D 66mm 70.58mm

Scale Factor When you compare corresponding measurements of proportional objects, you get a ratio. This ratio is called the scale factor.

Practice: Similar Polygons Worksheet