Question

What is the area of a regular pentagon with a side length of 9 millimeters and an apothem length of 6.2 millimeters

Answer 1

PENTA=5, so the pentagon is a 5-sided polygon.

on side's length is 9, so all sides added, namely the perimeter is 9+9+9+9+9, or 45.  We know the apothem is 6.2.

$\bf \textit{area of a regular polygon}\\\\ A=\cfrac{1}{2}(apothem)(perimeter)$