Answer:
The distance from the ground to the top of the ladder = 18.7 feet
Step-by-step explanation:
The distance from the ground to the top of the ladder is 9 feet more than the distance from the building to the base of the ladder.
distance from the building to the base of the ladder.= X
The distance from the ground to the top of the ladder = 9+x
Solving the triangle using Pythagorean theorem
X² +(x+9)²= 21²
X² + x² + 18x +81= 441
2x² +18x -360 = 0
X² +9x -180 = 0
X= (-9-28.3)/2 or (-9+28.3)/2
Definitely x is going to be a positive number
So
X= (-9+28.3)/2
X=9.65 feet
The distance from the ground to the top of the ladder = 9+x
The distance from the ground to the top of the ladder = 9+9.65
The distance from the ground to the top of the ladder = 18.65
The distance from the ground to the top of the ladder = 18.7 feet