Question

Please help and explain

Answer 1

Take a look at one of the triangles.  Base is 10 ft and height is sqrt(10^2-5^2), or h = sqrt(75) = 5sqrt(3).

Then the area of one such triangle is A = (1/2)(base)(height) 
                                                                = (1/2)(10)(3sqrt(3) ).
Since there are 2 such triangles, mult. this result by 2:  We get

                                                                     30sqrt(3).

This leaves us with the task of finding the area of the slant sides and of the base.  Base = 150 ft^2; 2 slant sides = 2(150 ft^2) = 300 ft^2.  Total 450 ft^2.

Now please evaluate   30sqrt(3)+450      ft^2.