A man 1.8 m tall look down from the top of a lighthouse 25m high and sees a ship at an angle of depression 35.how far is the ship from the foot of the lighthouse

Hi Salma, simply draw the figure. You have a right angle triangle with height (25+1.8) m and base, the unknown distance x
Angle opposite to the height is 35 deg
So tan 35 = 26.8 / x
Required x = 26.8 / tan 35
Hope you would complete the rest part.
All the best