The answer is 13 you have to add the top and bottom
These calculations are based on the drawing of the file enclosed.
There are three right triangles.
From the big right triangle:
a^2 + b^2 = 25^2
From the small right triangle on the left side:
(25-x)^2 + 10^2 = a^2
From the small right triangle on the right side
x^2 +10^2 = b^2
=> (25-x)^2 + 10^2 + x^2 + 10^2 = a^2 + b^2
=> (25-x)^2 + 10^2 + x^2 + 10^2 = 25^2
=> 25^2 - 50x + x^2 + 10^2 + 10^2 = 25^2
=> x^2 -50x + 100 =0
Use the quadratic formular to find the roots:
x = 2.1 and x = 47.9
Distance from back: 25 - 2.1 = 22.9 ft
Answer: 22.9 ft
X= 49 because the square root of 49 IS 7. :D
Good luck! :)
That would be B) B
hope it helps