Question

a soma dos ângulos internos de um eneagono e quanto?

Answer 1

S = ( N - 2 ) . 180
S = (9 - 2 ) . 180
S = 7 . 180
S = 1260°

Answer 2

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