Question

Observe a seguir semelhança de triângulo

Answer 1

$\frac{BC}{BE} = \frac{AC}{ AD} \\ \frac{12 \div 4}{20 \div 4} = \frac{15}{AD}$

$\frac{3}{5} = \frac{15}{ AD } \\ 3AD = 75 \\ AD = \frac{75}{3} \\AD = 25$