Question

A soma das medidas dos ângulos internos de um heptágono convexo ??

Answer 1

Si = 180(n-2)

Si= 180(7-2)

Si= 180*5 = 900.

Answer 2

$\large\displaystyle\boxed{\begin{array}{l} \sf \:S_i = (n - 2)\cdot180 {}^{ \circ} \rightarrow \begin{cases} \sf \: S_i =soma\;dos\;\hat{a}ngulos\; internos\\\sf\:n=n\acute{u}mero\;de\; lados\end{cases} \\ \sf \: S_i = (7 - 2) \cdot180 {}^{ \circ} \\ \\ \sf \: S_i = 5 \cdot180 {}^{ \circ} \\ \\ \boxed{ \boxed{ \sf{ S_i = 900 {}^{ \circ} }}}\end{array}}$