Question

b) The area of four walls of a room is 639 ft. If the breadth and height of the room 15.5 ft and 9 ft respectively, find the length.​

Answer 1

Explanation:

perimeter X height = area

(15.5 + 15.5 + L + L ) * 9 = 639 ft^2

(31 + 2L) * 9 = 639

31 + 2L = 639/9

L = 20 ft