Question

O valor do ângulo 420° em radianos é?

Answer 1

$\pi$ rad ------ 180°
x -------------- 420

180 x = $420 \pi rad$

x = $\frac{7}{3} \pi rad$

Answer 2

Regra de 3:

180  ----------------  π rad  
420  ---------------   x

$\boxed{x=\frac{420 \pi}{180}=\frac{7 \pi}{3} \ rad}$