# What will be the Height of Pole? If

The angle of elevation of sun changes from 30 degree to 45 degree , the length of the shadow of a pole decreases by 4 meters, the height of the pole is
( Assume √3 = 1.732)

1. 1.464 m
2.  9. 464 m
3.  3. 648 m
4.  5. 464 m

Manish Listener Asked on 9th July 2015 in

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Let height of pole be ‘h’,

First angle of elevation from sun to pole is 30 degree.
Distance between shadow pole to foot of pole = ‘x’
Therefore, tan30 = h/x
1/sqrt (3) = h/x.
x  = h * 1.732 ……(i)

Second angle of elevation angle from sun to pole is 45 degree,
Distance form foot of pole to shadow of pole = ( x – 4 ).
Therefore, tan45 = h / ( x – 4 )
1 = h / ( x – 4 )
x  = h + 4             ….(ii)
on comparing eqn. (i) and (ii) we get ,
h * 1.732 = h + 4
h (1.732 – 1 ) = 4
h  =  4 * 0.732
h  =  5.464
Hence, the height of pole is 5.464m

vijay Professor Answered on 13th July 2015.