Question

qual o valor de um ângulo interno de um icoságono​

Answer 1

aí = 180 -360/n

aí = 180 -360/20

aí = 180 - 18

aí = 162°

Answer 2

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