Question

The foot of ladder is 6 m away from a wall and its top reaches a window 8m above the ground. if the ladder is shifted in such a way thats its foot is 8 m away from the wall to what height does its top reach.

Answer 1

Distance from wall to foot of ladder AB  =  6 m 
And
Height of window  BC  =  8 m  
So,
Let length of ladder  AC  = x m 




Now we apply Pythagoras theorem in triangle ABC  , As  : 

AC2  =  AB2  + BC2 

x2  = 62  + 82 

x2  = 36  + 64 

x2  =  100 

x =  10 
So,
Length of ladder AC  =  10  m 

Now the distance of foot of ladder from wall  AB  =  8 m 
And
We know length of ladder AC  =  10 m 
So,
Height of tip of ladder BC  = h m 





Now we apply Pythagoras theorem in ABC , As  :

AC2  =  AB2  +  BC2 

102   =  82  + h2 

h2  = 100 - 64 

h2  = 36 

h   = 6 

So,
The tip reach at height of 6 m .