Question

an observer standing on top of a 80m lighthouse spots a ship in distress at an angle of depression of 45degree. find the distance the ship is from the shore

Answer 1

Answer:

Height of tower 80 m.

Two ships are at B and C.

Following the given figure, we can say

AC

AD

=tan60˚⇒

3

=

AC

80

⇒AC=

3

80

AB

AD

=tan30˚⇒

3

1

=

AB

80

⇒AB=80×

3

⇒AC+BC=80

3

⇒

3

80

+BC=80

3

⇒BC=80

3

−

3

80

BC=

3

160

BC=92.37 m

Nearest integer =92

solution