To find the height of the building using the ladder, we can use the Pythagorean theorem, which states that for a right triangle, the square of the length of the hypotenuse (c) is equal to the sum of the squares of the lengths of the other two sides (a and b). In this case:
- \( c = 797979 \) feet (the length of the ladder),
- \( a = 131313 \) feet (the distance from the base of the building to the bottom of the ladder),
- \( b \) is the height of the building (the side we want to find).
According to the Pythagorean theorem:
\[ c^2 = a^2 + b^2 \]
We can rearrange this to find \( b \):
\[ b^2 = c^2 - a^2 \]
Taking the square root of both sides will give us the height \( b \):
\[ b = \sqrt{c^2 - a^2} \]
Now, substituting the known values into the equation:
\[ b = \sqrt{797979^2 - 131313^2} \]
Calculating \( c^2 \) and \( a^2 \):
\[ 797979^2 = 636462048064 \ 131313^2 = 17243956869 \]
Now calculate \( b^2 \):
\[ b^2 = 636462048064 - 17243956869 = 619218091195 \]
Now take the square root to find \( b \):
\[ b = \sqrt{619218091195} \approx 78543.6 \]
Rounding to the nearest tenth, the height of the building is approximately:
\[ \boxed{78543.6} \text{ feet} \]