Help plz will give brainliest

What is the missing step in this proof ?

Pyotr tchaikovsky sporting goods operates on a 45% overhead based on the selling price, which results in an overhead of $65.34 on the newest version of an air hockey game set. if the air hockey game set costs pyotr tchaikovsky sports $49.32, find the selling price, the markup, and the net profit.

Someone me what is the area of this figure? 18m 18m 8m 16m