# Math Trig. Help!

• Sep 9th 2008, 11:11 AM
<3<3
Math Trig. Help!
An aircraft flies from its base 200km on a bearing 162 degrees, then 350 km on a bearing 260 degrees, and then returns directly to base. Calculate the length and bearing of the return journey!!!

• Sep 9th 2008, 11:41 AM
Simplicity
Quote:

Originally Posted by <3<3
An aircraft flies from its base 200km on a bearing 162 degrees, then 350 km on a bearing 260 degrees, and then returns directly to base. Calculate the length and bearing of the return journey!!!

Draw a diagram, it does half the question for you.

To work out the length it travels, use the cosine rule. $a^2 = b^2 + c^2 - 2bc\cos A$, where:
• $a,b,c$ are your lengths.
• $A$ is the angle opposite to the side $a$.
• Sep 9th 2008, 11:50 AM
shinhidora
As I replied to your other topic!

If you draw that out, you should en up with a triangle...

'B' being your first point where you change bearing