<PRE><B>Question 61142</B>
A
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B     C

Let AB be the building, AC be the ladder and 

BC is the distance between feet of ladder to the foot of the building.

Given the height of the ladder = 15ft

The distance between feet of ladder to the foot of the building = 7ft.

Using Pythagoras theorem, we find the length of the building which is AB.

AC^2  = AB^2 + BC^2

15 ^2 = AB^2 + 7^2

225   = AB^2   + 49

225 -49 = AB^2

176 = AB^2

Taking the square root, we get

13.26 = AB

Therefore the length of the building is 13.26 feet.
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