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Complete the Bell Work Handout Bell Work Write a congruence statement. M T R ∆MNL ≅ ∆SRT N L S Similar Polygons • Two objects are similar if they are the same shape but different sizes. Example: Is the pair of polygons similar? Explain your answer. 5m 8m 10 m 13 m 5 8 10 13 5(13) = 10(8) 65 = 80 NO OR 5 10 8 13 5(13) = 8(10) 65 = 80 NO Example: Is the pair of polygons similar? Explain your answer. 4 yd 3 yd 4.5 yd 6 yd 4 3 6 4 .5 4(4.5) = 6(3) 18 = 18 YES OR 4 6 3 4 .5 4(4.5) = 6(3) 18 = 18 YES Are the polygons similar? You must be able to justify your answer. (Shapes not drawn to scale.) Yes No 15 ft 9 ft 12 ft 21 ft Are the polygons similar? You must be able to justify your answer. (Shapes not drawn to scale.) Yes No 10 m 8m 2.5 m 2m Are the polygons similar? You must be able to justify your answer. (Shapes not drawn to scale.) Yes No 15 yd 6 yd 37.5 yd 15 yd Example: Find the value of x in the pair of similar polygons. 15 cm x 6 cm 10 cm 8 cm 15 6 x 10 15(10) = 6x 150 = 6x 25 cm = x 15 x OR 6 10 15(10) = 6x 150 = 6x 25 cm = x You try: Find the value of y in the pair of similar polygons. 15 in 7.5 in 5 in y 15 7.5 y 5 15(5) = 7.5x 75 = 7.5x 10 in = x Or 15 y 7 .5 5 15(5) = 7.5x 75 = 7.5x 10 in = x Find the measure of the missing value in the pair of similar polygons. (Shapes not drawn to scale.) 17.5 ft 25 ft 25 ft 18 ft A 18ft B 450ft C 12.6 ft D .07 ft w Find the measure of the missing value in the pair of similar polygons. (Shapes not drawn to scale.) x 4m 4.25 m 17 m A 16m B 16.25m C 68ft D 18.06ft Find the measure of the missing value in the pair of similar polygons. (Shapes not drawn to scale.) y 6 mm 11 mm A 66mm B 70.58mm C 33.5mm D 21 mm 38.5 mm Scale Factor • When you compare corresponding measurements of proportional objects, you get a ratio. • This ratio is called the scale factor. What is the scale factor from the larger shape to the smaller one? Practice: Similar Polygons Worksheet