A rectangle has a perimeter of 40 in. and a length of 15 in. What is its area?

The perimeter is is all 4 sides added together

so 15 + 15 is 30 and 5+5 would be 10 more to make 40

so length is 15in and width is 5in

to find the area

A = l * w

a = 15*5

area is 75in

The perimeter is 2*length + 2*width. 2*length is 30 in. So, 2*width is 10 in. Giving width = 5 inches.

Area = length * width = 15*5 = 75 square inches.