Question

From an airplane at an altitude of 1200m the angle of depression to a building one the ground measures 28 degrees. Find the distance from the plane to the building

Answer 1

Check the picture below.

now, we're assuming "to the building" means "to the ground", since we don't know the building's height, so we're also assuming the 1200m is above the building, as you see in the picture.

make sure your calculator is in Degree mode.