Question

please help me by solved this

my copy has to be checked tomorrow



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Answer 1

the wall is a triangle. To find the area, calculate by:

A = b×h/2. First, we must to find the height h. Then:

define m + n = 15. By Pythagoras' theorem:

121 = h^2 + m^2 and

36 = h^2 + n^2.. Solving for h^2:

121 - m^2 = h^2 and 36 - n^2 = h^2. And so:

121 - m^2 = 36 - n^2. But n = 15 - m. Then:

121 - m^2 = 36 - (15 - m)^2. Expanding:

121 - m^2 = 36 - (225 - 30m + m^2).

121 - m^2 = 36 - 225 + 30m - m^2. Solving for m, we have:

310 = 30m

m = 10.34m. Replacing:

121 = h^2 + 10.34^2

h = 3.75m

The area:

A = (15×3.75)/2 = 28.125 m^2