Answer: 7.9 ft.
Step-by-step explanation:
Given : The length of ladder = 12 ft.
The distance of bottom of the ladder from the side of the house = 9^29 ft.
Since the side of the house must be standing vertical to the ground makinf right angle, then the triangle made by ladder must be a right angle with hypotenuse (Side opposite to right angle) = 12 ft.
Let x be the height of the top of the ladder from the ground.
Using the Pythagoras theorem of right triangles, we have
![12^2=9^2+x^2\\\\\Rightarrow\ x^2=144-81\\\\\Rightarrow\ x^2=63\\\\\Rightarrow\ x=\sqrt{63}=7.9372539331\approx7.9](https://tex.z-dn.net/?f=12%5E2%3D9%5E2%2Bx%5E2%5C%5C%5C%5C%5CRightarrow%5C%20x%5E2%3D144-81%5C%5C%5C%5C%5CRightarrow%5C%20x%5E2%3D63%5C%5C%5C%5C%5CRightarrow%5C%20x%3D%5Csqrt%7B63%7D%3D7.9372539331%5Capprox7.9)
Hence, the height of the top of the ladder from the ground = 7.9 ft.