What is the height of the television tower to the nearest foot?

Delores and Bill are standing 100 feet apart in a straight line with the WWV television tower. The angle of the elevation from from Bill to the tower is 30° and the angle of the elevation from Dolores is 20°. Find the height of the television tower to the nearest foot.

Tan(30) = height of tower / distance to tower

Tan(20) = height of tower / distance to tower + 100 ft

.5774 = h / d

.3640 = h / (d + 100)

.5447 d = h

.3640 (d + 100) = h

.5447 d = .3640 (d + 100)

.5447 d = .3640 d + 36.4

.1807 d = 36.4

d = 201.44 ft

.5774 (201.44) = h

h = 116.31 ft