trigonometry

Question

Hannah walks 6 km on the bearing of  159° then 9 km on a bearing of 252°.  On what bearing must Hannah walk to return to her starting point and how much further must she walk?

Answer 1

Draw a label a diagram.

Bearing is measured from clockwise from north (positive ordinate)

A is Hannah's starting point. She walks into QIV.

B is Hannah's turning point. She walks into QI.

C is Hannah's point of return.

 

AB = 6, BC = 9

m∠A = 69°, m∠B = 129°. Now calculate m∠C.

 

Use Law of Sines or Law of Cosines to determine CA.