Question

No triângulo abaixo determine o valor de cada ângulo interno.
A=?
B=?
C=?

Answer 1

O ângulo externo de um triângulo é igual a soma dos ângulos internos não adjacentes a ele, ou seja :

$3\text x-30 =\text x-10+ \text x+30$

$3\text x-30 =2\text x+20$

$\boxed{\text x = 50}$

Ângulos internos :

$\text A = \text x-10 \to \text A = 50-10\\\\ \to \huge\boxed{\text A=40}$

$\text B = \text x+30 \to \text B = 50+30\\\\ \to \huge\boxed{\text B=80}$

$\text{A+B+C = 180} \to 40+80+\text C =180 \\\\\to \text C =180-80-40 \\\\\to \huge\boxed{\text C = 60}$