Frame has a perimeter of 36 inches if the frame is 10 inches wide what would the area be?

it is obvious that the frame is in the shape of a rectangle

P = 2L + 2W
36 = 2L + 2(10)
36 = 2L + 20
subtract 20 from both sides
36 - 20 = 2L + 20 - 20
16 = 2L
divide both sides by 2
16/2 = 2L/2
8 inches = L

A = LW
A = 8 * 10
A = 80 square inches