Question

veja o pentágono Determine o número de diagonais desse polígono ​

Answer 1

d = n.(n-3)/2

d = 5.(5-3)/2

d = 5.(2)/2

d = 5 diagonais

Answer 2

$\Large \text{ \sf{ d = \dfrac{n \cdot(n - 3)}{2} } }$

$\Large \text{ \sf{ d = \dfrac{5 \cdot(5 - 3)}{2} } }$

$\Large \text{ \sf{ d = \dfrac{5 \cdot2}{2} } }$

$\Large \text{ \sf{ d = \dfrac{10}{2} } }$

$\Large \text{ \boxed{ \boxed{\sf{ d = 5}}} }$