Answer: 9.16 feet
Explanation:
Hi, to answer this question, since we have formed a right triangle (see attachment) we have to apply the Pythagorean theorem:
a2 +b2 = c2
Where c is the hypotenuse of a right rectangle (the longest side) and a and b are the lengths of the other 2 sides.
In this case the hypotenuse us the ladder.
So, replacing with the values:
4^2 + b ^2 = 10^2
16 + b^2 = 100
b^2 = 100-16
b^2 = 84
b = √84
b= 9.16 feet