Question

04. Determine o angulo interno de um icoságono.
A) 1260°
B) 270°
C) 360°
D) 630​

Answer 1

ae = 360/n = 360/20 = 18°

ai = 180 -ae = 180 -18 = 162° ✓

parece A)

Answer 2

$\large\displaystyle\boxed{ \begin{array}{l} \sf \: A_i = \dfrac{(n - 2) \cdot180 {}^{ \circ} }{n} \\ \\ \sf \:A_i = \dfrac{(20 - 2) \cdot180 {}^{ \circ} }{20} \\ \\ \sf \: A_i = \dfrac{18 \cdot180 {}^{ \circ} }{20} \\ \\ \sf \:A_i = \dfrac{3240 {}^{ \circ} }{20} \\ \\ \boxed{ \boxed{ \sf{A_i = 162 {}^{ \circ} }}} \end{array}}$