Check P213 Master Strengthen P215 Extend P219 Test P223 9.5 Solving geometry problems You will learn to: Fluency Find the missing numbers in each equivalent ratio. • 4 : 6 = 8 : u • 3 : 2 = u : 8 • 5 : 7 = u : 21 • 2 : 5 = 9 : u Why learn this? Surveyors use similar triangles to find out the heights of tall structures. Explore Can you use triangles to find the height of a tree? Exercise 9.5 1 Are these triangles similar? Explain. Warm up CONFIDENCE • Use similarity to solve problems in 2D shapes. 2 These shapes are similar. Find the missing side, x. E B 15 cm x 12 cm 4 cm A C 6 cm D 18 cm F 3 Reasoning a Explain why angle a = angle e. c b a e d f b Which angle is equal to angle b? Explain. c Which angle is equal to angle f? Explain. Unit 9 Scale drawings and measures 210