Answer:
Step-by-step explanation:
This is a classic right triangle problem using Pythagorean's Theorem. The ladder's length is the hypotenuse of the triangle and the length from the building to the base of the ladder is the length of the base of the right triangle. We are looking for the height of the wall, which is also the height of the right triangle, which is also the missing leg in our formula:
[tex]13^2=7^2+y^2[/tex] and
[tex]169=49+y^2[/tex] and
[tex]y^2=120[/tex] so
y = 10.9 feet
