Review question

# Can we show this triangle is right-angled and find its area? Add to your resource collection Remove from your resource collection Add notes to this resource View your notes for this resource

Ref: R5442

## Suggestion

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

1. Prove that $\widehat{PQR}=90^\circ$.

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

1. 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.