Question

Please don’t only answer this explain how to figure it out so I have it for future reference

Answer 1

The polygon is built of 7 triangles (picture).

$P=7\cdot\dfrac{1}{2}ah\\ a=28.9 \text{ m}\\ h=30 \text{ m}\\\\ P=7\cdot\dfrac{1}{2}\cdot28.9\cdot30\\ P=3034.5 \text { m}^2 \Rightarrow C$