Question

Calcular a soma dos ângulos internos de um eneagono?

Answer 1

o eneagono tem 9 lados 

portanto

sn = 180 ( 9- 2 )

sn = 180 * 7
sn = 1260

Answer 2

$\large\displaystyle\boxed{\begin{array}{l}\sf{\displaystyle{\sf{S_i = (n - 2)\cdot180 {}^{ \circ} }}} \\ \\ \sf{S_i = (9 - 2) \cdot180 {}^{ \circ} } \\ \\ \sf{S_i = 7 \cdot180 {}^{ \circ} } \\ \\ \boxed{ \boxed{ \sf{S_i = 1260 {}^{ \circ} }}}\end{array}}$