Given that rectangle EFGH ~ rectangle WXYZ, find t. Similar Figures and Proportions COURSE 3 LESSON t = 12 3 Write the cross products. t = 4 Simplify. 9t99t Multiply. Then divide each side by 9. = t3t Substitute. = EF WX EH WZ EF corresponds to WX. EH corresponds to WZ. = 5-5

Similar Figures and Proportions COURSE 3 LESSON 5-5 A model train set has a passenger car that is 21.6 in. long. Its actual length is 72 ft. How long will the model for an 80-ft freight car be? The model car and the actual car are similar. Write a proportion. Words Let x = model freight car length. model passenger car length actual passenger car length model freight car length actual freight car length = Proportion 21.6 in. 72 ft x 80 ft = = 72 x Write the cross products. 1,728= 72xSimplify. 24= xSimplify. 1, x 72 = Divide each side by 72. The length of the model freight car is 24 in. 5-5

RST ~ PSU. Find the value of d. Similar Figures and Proportions COURSE 3 LESSON d = Write the cross products. Simplify.12d = 294 Divide each side by d = d = 24.5Simplify. Step 1 Separate the triangles as shown at the right. Substitute. SR SP RT PU d = = Step 2 Write a proportion using corresponding sides of the triangles. 5-5

Similar Figures and Proportions 1.Are the triangles similar? Explain. 2.A model of a building is 18 in. tall and 24 in. wide. The building is 30 ft tall. How wide is the building? COURSE 3 LESSON 5-5 No; their sides are not proportional. 40 ft 5-5