Answer: 8 feet
Step-by-step explanation:
It might help to draw out what's going on. You should draw out a right triangle. We know a = 6 is one of the legs while b is the unknown leg. The hypotenuse is c = 10. Use the pythagorean theorem.
a^2 + b^2 = c^2
6^2 + b^2 = 10^2
36 + b^2 = 100
b^2 = 100-36
b^2 = 64
b = sqrt(64)
b = 8
The top of the ladder can reach 8 feet off the ground.