Question

Atraves da formula d=n(n-3) /2 calcule o numero de diagonais do decagono ?

Answer 1

d=n(n-3)
      2
d=10(10-3)
        2
d=10*7
       2
d=35
Resposta: 35 diagonais

Answer 2

$\large\boxed{\begin{array}{l} \rm{d = \dfrac{n \cdot(n - 3)}{2}} \\ \\ \rm{d = \dfrac{10 \cdot(10 - 3)}{2} } \\ \\ \sf{d = \dfrac{10 \cdot7}{2} } \\ \\ \rm{d = \dfrac{70}{2} } \\ \\ \rm{d = 35} \end{array}}$