Question

ajuda no 11 pfv .........

Answer 1

Trigonometria básica, utilize o seno do ângulo compreendido entre as retas CB e CA.

$sen = \frac{cat. oposto}{hipotenusa}$

Portanto:

$sen 40 = \frac{7}{X}$

$X * sen 40 = \frac{7}{X} * \frac{X}{1}$

$X * sen 40 = \frac{7}{1}$

$X = \frac{7}{sen 40}$

$X = \frac{7}{0,64}$

$X = 10,9375$