The height of the tower is .

Let be the height of the building.

Let be the distance between tower and building.

The angle of elevation from the base of an office building to the tower is .

The angle of elevation from the roof of the building to the top of the building is .

(a)

Consider .

.

.

The distance between the office building from the Freedom Tower is .

(b)

Consider .

Substitute .

.

The height of the office building is .

(a) The distance between the office building from the Freedom Tower is .

(b) The height of the office building is .