Question

determine a soma das medidas dos angulos internos de um eneagono

Answer 1

o eneagono tem 9 lados
Formula:
Si(soma dos angulos internos)=(n {numero de lados} -2)·180
Si=(9-2)·180
Si=7·180
Si=1260

Answer 2

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