Ship A is 7.5km North of a lighthouse. Ship B is 3.4km East of the same lighthouse. What is the distance between these two ships?
You should draw a little sketch of the scenario. We should mark out our lighthouse location and roughly where the two ships would be in relation to the lighthouse. Then we should add any further information we have: the 7.5km length and the 3.4km length. Hopefully now you will see a shape, that being a right angled triangle - and only one length is missing which happens to be what we're looking for.We should immediately be thinking about what we know about right angled triangles; yes we have SOH CAH TOA, but we also have Pythagoras. Pythagoras is the appropriate choice because it only has one unknown (as oppose to the trigonometry where all angles AND the hypotenuse are unknown). With the standard a2+b2=c2 we know that we are missing the hypotenuse "c". "a" and "b" are interchangeable. The SQRT of ( 7.52+ 3.42) = 8.23km and that is our answer.
