7. Five mark example problem I

An Aeroplane leaves an airport and flies due north at a speed of 1000 \(km/hr\). At the same time, another aeroplane leaves the same airport and flies west at a speed of 1200 \(km/hr\). How far apart will be the two planes after \(1\frac{1}{2}\) hours?

 

The distance between two aeroplanes after \(1\frac{1}{2}\) hours \(=\) $i\sqrt{i}\mathit{km}$

 

The theorem used to find the distance between two aeroplanes \(=\) Thales theoremPythagoras theoremSimilar trianglesAngle bisector theorem