Question

Quanto mede os ângulos internos de um dodecágono regular?

Answer 1

Si = (12 - 2) · 180
Si = 10 · 180
Si = 1800

1800 : 12 = 150 <= cada ângulo mede

Answer 2

$\large\boxed{\begin{array}{l} \sf \:A_i = \dfrac{(n - 2) \: . \: 180 {}^{ \circ} }{n} \\ \\ \sf \: A_i = \dfrac{(12 - 2) \: . \: 180 {}^{ \circ} }{12} \\ \\ \sf \: A_i = \dfrac{10 \: . \: 180 {}^{ \circ} }{12} \\ \\ \sf \: A_i = \dfrac{1800 {}^{ \circ} }{12} \\ \\ \boxed{ \boxed{ \sf{A_i = 150 {}^{ \circ} }}}\end{array}}$