Review Quiz: 1. Maria is 4 ft 2 in. tall. To find the height of a flagpole, she measured her shadow and the pole’s shadow. What is the height h of the flagpole? 2. A blueprint for Latisha’s bedroom uses a scale of 1 in.:4 ft. Her bedroom on the blueprint is 3 in. long. How long is the actual room? 25 ft 12 ft

Parts of Similar Triangles Section 6-5

Proportional Perimeters Theorem If 2 triangles are similar, then the perimeters are proportional to the measures of the corresponding sides.

Example: Using Ratios to Find Perimeters Given that ∆LMN~∆QRS, find the perimeter P of ∆QRS. The similarity ratio of ∆LMN to ∆QRS is So the ratio of the perimeters is also 13/9.1. The perimeter of ∆QRS is 25.2 cm. 13P = 36(9.1) P = 25.2

The perimeter of ∆ABC is 14 mm. Example: ∆ABC ~ ∆DEF, BC = 4 mm, and EF = 12 mm. If P = 42 mm for ∆DEF, find the perimeter of ∆ABC. 12P = 42(4) P = 14 mm The perimeter of ∆ABC is 14 mm.

Example: Using the Triangle Angle Bisector Theorem Find PS and SR. x = 30

Example: Find AC and DC. y = 18 So DC = 9 and AC = 16.

Lesson Quiz: Part I Find the length of each segment. 1. 2. SR = 25, ST = 15

Lesson Quiz: Part II 3. ∆ABC ~ ∆DEF. Find the perimeter of ∆ABC. P = 27 in.