The top of a ladder leans against a house at a height of 12 feet. The length of the ladder is 8 feet more than the distance from the house to the base of the ladder. Find the length of the ladder?

1 Answer
Mar 19, 2016

13ft13ft

Explanation:

magoosh

The ladder leans against a house at a height AC=12 ftAC=12ft
Suppose distance from the house to the base of ladder CB=xftCB=xft
Given is that length of ladder AB=CB+8=(x+8) ftAB=CB+8=(x+8)ft
From Pythagorean theorem we know that
AB^2=AC^2+CB^2AB2=AC2+CB2, inserting various values
(x+8)^2=12^2+x^2(x+8)2=122+x2
or cancel(x^2)+16x+64=144+cancel(x^2)
or 16x=144-64
or 16x=80/16=5
Therefore length of ladder =5+8=13ft

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Alternatively, one can assume length of ladder AB=xft
This sets the distance from the house to the base of ladder CB=(x-8)ft
Then proceed with setting up of equation under Pythagorean theorem and solve for x