Question

The angle of elevation of a tower from a point on the same level as the foot of the tower is 30.,on advancing 150m towards the foot of the tower the angle of elevation of the tower becomes 60. , find the height of the tower {use root 3=1.732}

Answer 1

 let the height of the building be h m 
then AB =h m 
in right angle triangle PQR tan 60°=PQ/BQ
=>√3=30/BQ=>BQ
30/√3m=30√3/3m =10√3
in the trialgle ABQ
tan30°=AB/BQ 
=>1/√3=h/BQ =>h =BQ/√3
=>h =10√3/√3 =10
HENCE THE LENGTH OF BUILDING =hm=10m