Question

a)qual a soma das medidas dos ângulos internos de icosagono regular?

Answer 1

$\large\displaystyle\boxed{\begin{array}{l} \sf \: S_i = (n - 2) \cdot180 {}^{ \circ} \\ \\ \sf \: S_i = (20 - 2) \cdot {180}^{ \circ} \\ \\ \sf \: S_i = 18 \cdot180 {}^{ \circ} \\ \\ \boxed{ \boxed{ \sf{S_i = 3240 {}^{ \circ} }}}\end{array}}$

Answer 2

$\sf S_i=(n-2)\cdot180^\circ$

$\sf S_i=(20-2)\cdot180^\circ$

$\sf S_i=18\cdot180^\circ$

$\red{\sf S_i=3240^\circ}$