Originally Posted by

**dontpanic** Hi,

I've a similar problem to the one below but I don't quite understand how they arrived at the answer.

*"A boat travels from point A, to B, to C, then back to A.*

The bearing from A to B is S 27 degrees E

The bearing from B to C is N 57 degrees W

The bearing from C to A is N 16 degrees E

If this route was in the form of a triangle, what would the three angles of the triangle be?"

**Answer**

A = 16+27 = 43 degrees

B = 30 degrees

C = 107 degrees

I don't understand why 16+27 were added together to get A nor how B is 30. No matter what combination of subtracting or adding 90 degrees do I get 30.

Any help is much appreciated, Geometry & Trig are my weak points in Maths.