Question

Could someone with number 2 a

Answer 1

The sum of the interior angles of a polygon with $n$ sides is

$180(n-2)$

Since a pentagon has 5 sides, the sum of its interior angles is

$180(5-2) = 180 \cdot 3 = 540$

Since it is a regular pentagon, all sides and angles are the same, so one single angle measures

$\dfrac{540}{5} = 108$ degrees.