Trigonometry test

Question

A cell phone company built a cell tower between two towns. A triangle can be drawn with the tower and two towns. Town A is located 6.3 km away and Town B is located 6.2 km away. If the angle formed at the tower is 65°, what is the distance between the two towns, to the nearest tenth of a kilometer?

Answer 1

use the law of cosines

AB^2 = 6.3^2 + 6.2^2 - 2(6.3)(6.2)cos65

then take the square root to get AB the distance between the 2 towns