SOLUTION: A 20 foot ladder is placed against a building in such a way that the distance from the top of the ladder to the ground is 4 feet more than the distance from the bottom of the ladde

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Question 838146: A 20 foot ladder is placed against a building in such a way that the distance from the top of the ladder to the ground is 4 feet more than the distance from the bottom of the ladder to the wall. Find the distance from the bottom of the ladder to the wall.
Answer by mananth(16946) About Me  (Show Source):
You can put this solution on YOUR website!
distance from wall to the foot of ladder be x
The distance from top of ladder to the ground=(x+4)
Ladder length = 20 feet
The ground wall and ladder form a right triangle
apply Pythagoras theorem
x^2+(x+4)^2=20^2
x^2+x^2+8x+16=400
2x^2+8x-400+16=0
2x^2+8x-384=0
/2
x^2+4x-192=0
complete the squares
x^2+4x+4-4-192=0
(x+2)^2= 196
take the positive square root
x+2=13
x=11
(x+2)=13
distance from wall to the foot of ladder 11 feet
The distance from top of ladder to the ground=13 feet