Seatwork No. 1

An airplane starts from a station and rises at an angle of 10° with the horizontal. By how many feet will it clear a vertical wall 110ft. high and 900ft. from the base?
Use: tan 10° = 0.176
Given:
100 ft. = height of the wall
900 ft. = distance from the base of the wall to the station
A = 10°

Required: x

Solution:
Fig. 1.1

Tan 10° = (100 ft. + x) / 900 ft.
0.176 = (100 ft. + x) / 900 ft.
0.176 x 900 ft = 100 ft + x
158.40 ft = 110 ft + x
158.40 ft – 110 ft = x
48.40 ft = x