Question

please answer this question​

Answer 1

$area \: of \: four \: walls \: = 1040 \\ 2(l + b)h = 1040 \\ 2(x + x) \times 20 = 1040 \\ 4x \times 20 = 1040 \\ 4x = 52 \\ x = \frac{52}{4} = 13m \\ so \: the \: side \: of \: the \: room = 13m$