Three points have co-ordinates \(P\,(-2, -3)\), \(Q\,(2, 0)\), \(R\,(8, -8)\).

- Prove that \(\widehat{PQR}=90^\circ\).

What do you know about perpendicular lines? When are two lines perpendicular?

- Calculate the length of \(PR\) and hence, or otherwise, find the perpendicular distance of \(Q\) from \(PR\).

How does computing the length of \(PR\) help to find the perpendicular distance of \(Q\) from \(PR\)? Maybe a sketch could help us see a connection.