Question

select two proportions that could be used to solve for the missing lengths.
□ $\frac{10}{ef}=\frac{5}{3}$
■ $\frac{3}{5}=\frac{ab}{15}$
□ $\frac{ab}{15}=\frac{3}{10}$
□ $\frac{3}{10}=\frac{5}{ef}$

Explanation:

Step1: Use similarity of triangles

For similar - triangles, ratios of corresponding sides are equal.

Answer:

$\frac{3}{5}=\frac{AB}{15}$ (already given as correct), assume another triangle with sides in proportion. If we consider the correct proportion based on similar - triangle side - length relationships, another could be $\frac{AB}{15}=\frac{3}{10}$ (assuming appropriate corresponding sides). So the two proportions are $\frac{3}{5}=\frac{AB}{15}$, $\frac{AB}{15}=\frac{3}{10}$