The foot of a ladder is 6 m away from a wall and its top reaches a window 8 m above the ground. If the ladder is shifted in such a way that its foot is 8 m away from the wall, to what height does its tip reach?
Let length of ladder be AD=BE=1m
In
ACD
AD2=AC2+CD2
t2= 82+62 ………………..(i)
In 
BCE
BE2=BC2+EC2
t2= BC2+82 …………….. (II)
From (i) and (ii)
BC2+82=82+62
BC2=62
BC=6m
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