Question

calcular a + b de acordo com a figura abaixo

Answer 1

Teorema de Tales

$\frac{a}{12}=\frac{3}{a}$

$a^2=12\times3\\a^2=36\\a = \sqrt{36}\\\\\boxed{a = 6}$

$\frac{b}{a}=\frac{9}{3}$

$6b=9a$

$b=\frac{9\times a}{6}$

$b=\frac{9\times6}{6}$

$\boxed{b = 9}$

Resposta: a + b = 6 + 9 = 15