Question

UM POLÍGONO DE 11 LADOS TEM QUANTAS DIAGONAIS?
(a) 18
(b) 25
(c) 30
(D) 33 ​

Answer 1

$\boxed{\begin{array}{l}\sf n=11\\\sf d=\dfrac{n\cdot(n-3)}{2}\\\\\sf d=n\cdot\dfrac{11\cdot(11-3)}{2}\\\\\sf d=\dfrac{11\cdot\backslash\!\!\!8}{\backslash\!\!\!2}\\\\\sf d=11\cdot4\\\sf d=44~diagonais\\\sf corrija~o~gabarito.\end{array}}$