Draw and explain an angle of elevation of the top of a building is 60 degrees and the angle of depression of its base is 15 degrees observed from a window of another building 15m.away.

Sketch the 2 buildings, mark the window on one of them.

Draw a horizontal from the window to the other building, mark it as 15m
(any horizontal line between the two buildings will be 15m )
From the window draw in lines to the top and bottom of the opposite building.
Mark your given angles. You have right-angled triangles.

Btw, I see no question asked in your problem.