Question

an observer from the top of a 100m light house from the sea level the angle of depression of two ship are 30 and 45 .if one ship is exactly behind the other on the same side of the light house find distance between two ship.

Answer 1

Heya....!!!!!

IN ∆ ACD

tan45° = AD / DC

=> 1 = 100/DC

=> DC = 100M

in ∆ ABD,

tan30° = AD/DB

=> 1/√3 = 100/DB

=> DB = 100√3

=> DB = 100√3M


DB = DC + CD

=> 100√3= 100 + CD

=> (100√3 - 100) = CD

=> 100(1.732 - 1) = CD
[ √3 = 1.732 ]

=> CD = 100×0.732

=> CD = 73.2M