1.

If the angles of elevation of the top of a tower from 2 points at the distance of 4m and 25m from the base of the tower and in the same line with it are complimentary, what is the hight of tower​

Answer»

Step-by-step explanation:

solution:-

given AB is TOWER

p and q are the point of 4m and 25 m

from fig PB=4m ,BQ=25m

angle \: of \: elevation \: from \: p \: be \:  \alpha

and \: angle \: of \: elevation \: from \: q \: be \:  \beta

given  :  \alpha  +  \beta  = 90 \degree

in triangle ABP

\tan( \alpha )  =  \frac{ab}{bp}

in triangle ABQ

\tan( \beta )  =  \frac{ab}{bq}

now we WRITE as

\beta  = 90 -  \alpha

so put the value on tan(beta), we get

\tan(90 -  \alpha )  =  \frac{ab}{bq}

now , we get

\cot( \alpha )  =  \frac{ab}{bq}

\frac{1}{ \tan( \alpha ) }  =  \frac{ab}{bq}

\tan( \alpha )  =  \frac{bq}{ab}

now

\tan( \alpha )  =  \frac{ab}{bp}  =  \tan( \alpha )  =  \frac{bq}{ab}

so we can write :-

\frac{ab}{bp}  =  \frac{bq}{ab}

use cross multiplication

AB²=BQ×BP

AB²=25×4

AB²=100

AB=10m

height of tower is 10 m



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