1. EXAMPLE 1 Use similarity statements b. Check that the ratios of corresponding side lengths are equal. In the diagram, ∆RST ~ ∆XYZ a. List all pairs of congruent angles. c. Write the ratios of the corresponding side lengths in a statement of proportionality.

2. EXAMPLE 1 Use similarity statements TR ZX = 25 15 = 5 3 c. Because the ratios in part (b) are equal, SOLUTION YZ RS XY = ST = TR ZX. a.R = ~ ~~ == X,X, S Y TZ and RS XY = 20 12 = 5 3 b. ; ST = 30 18 = 5 3 YZ ;

3. GUIDED PRACTICE for Example 1 SOLUTION J = ~ ~~ == P,P, K Q LR and The congruent angles are JK PQ = KL QR = LJ RP The ratios of the corresponding side lengths are. L J K R P Q 1. Given ∆ JKL ~ ∆ PQR, list all pairs of congruent angles. Write the ratios of the corresponding side lengths in a statement of proportionality.