Question

an helicopter at an altitude of 200 m finds that two boats are sailing towards it in the same direction the angle of depression of the boats are observed from the aeroplane are 45 degrees and 60 degree respectively find the distance between two boots

Answer 1

Consider the helicopter as point A.The helicopter is at altitude of 200 m ,therefore distance between sea surface helicopter is 200m. Draw a perpendicular from point A to sea surface and name it as B. Let the first boat be at point C and second at point D. The angle of depression is congruent to angle of elevation. Therefore  in right angled triangle ABC angle C is 45 degree.Therefore BC = AB = 200m. Now similarly in ABD angle D is of 60 degree. Therefore  AD= 200/ 1.732 i.e root 3. AD=115.47
CD=200-115.47=84.53m