MAC 1114 Trigonometry
Section 7.1: The Law of Sines
1) In triangle ABC, A = 80°, B = 30°, and b = 14.0 cm. Find the length of side a.
2) Find the missing parts of triangle ABC if B = 57°, C = 31°, and a = 7.3 cm.
3) A man standing near a radio station antenna observes that the angle of elevation to the top of
the antenna is 64°. He then walks 100 feet further away and observes that the angle of
elevation to the top of the antenna is 46°. Find the height of the antenna to the nearest foot.
4) A woman stands at point A facing a tree and finds the angle of elevation from A to the top
of the tree to be 51°. Then the woman turns 105° and walks 25 feet to point B where she
measures the angle between her path AB and the line BC extending from her to the base of
the tree. She finds that angle to be 44°. Find the height of the tree.
5) A ship is anchored off a long straight shoreline that runs north and south. From two
observation points, 18 miles apart on shore, the bearings of the shop are N 31° E and S 53° E.
What is the distance from the ship to each of the observation points?
6) A traffic light weighing 22 pounds is suspended by two wires. Find the magnitude of the
tension in wire AB, and the magnitude of the tension in wire AC.
B C
T2 45° 60° T1
A
1