Question

The area of the 4 walls of a room is 77sqm. The length and height of the room are 10m and 4m respectively. Find the height of the room.
$area \: of \: the \: four \: room \: = 2(l +b) \times h$
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Answer 1

Answer:

$lateral \: surface \: area = 2h(l + b) \\ 77 = 2(4)(10 +b ) \\ 77 = 8 \times 10 + 8 \times b \\ 77 = 80 + 8b \\ 80 + 8b = 77 \\ 8b = 77 - 80 \\ b = \frac{3}{8 } \\ b = 0.375$