Pythagoras Q3

A plane leaves airport A and flies directly north for 30km to airport B where it turns on a bearing of 090 degrees and flies for 40km to airport C.

How far is airport A from airport C?

SOLUTION

The first thing to do is to draw a diagram.

We can now use Pythagoras' Theorem as follows:

So, airport A is 50km from airport C.

Notice that we have 3 integer values for the 3 lengths i.e. we have a Pythagorean Triple 30, 40, 50.