Set this up as a proportion, knowing that the 2 trapezoids are similar. The ratios will reflect corresponding sides. I used these: [tex] \frac{13.5}{9}= \frac{3}{A} [/tex]. Cross-multiply to solve for A: 13.5A=27. Divide both sides by 13.5 to get A = 2. The length of A is 2 cm
