MPM 2D/G Lesson 7.8
Cosine Law Word Problems
Ex. 1
Jon rides his bike due east for 10 km. Angela rides her bike East 25° South (E25°S) for 7 km.
How far apart are Jon and Angela, to the nearest 10th of a km?
Ex. 2
A race follows a triangular course. The 3 legs of the course are, in order, 2.3 km, 5.9 km, and
6.2 km. Find the angle between the starting and finishing legs to the nearest degree.
Ex. 3
Two boats left harbour at the same time. On traveled at 10 km/h on a course of N47°W. The other
traveled at 8 km/h on a course of N79°W. How far apart are they, to 1 decimal place, in 2 hours?