Question

a soma das medidas dos angulos internos de um eneagono e

Answer 1

Eneágono ==> 09 lados
n = 9

S = (n - 2) * 180°
S = (9 - 2) * 180°
S = 7 * 180°
S = 1260°

Answer 2

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