Let's consider the figure is a triangle, in which perpendicular is the Height of the building whereas actual distance of H and K from top of the building would be corresponding Hypotenuse.
Now, Sin Ф = P / H
Sin 43 = 72 / H
H = 72 / Sin 43
H = 72 / 0.68 [ Sin 43 = 0.68 ]
H = 105.88 meters
Now, Sin 54 = 72 / H
K = 72 / Sin 54
K = 72 / 0.80
K = 90 meters
Hope this helps!