Question

Line segment $PQ=12cm$ and $R$ is a point on it such that $PR=8cm$. Then find $P{Q}^2-P{R}^2$.

Answer 1

$QR=PQ-PR$

$=12-8=4$cm

$P{Q}^2-P{R}^2=(12{)}^2-(8{)}^2$

$=144-64$

$=80$cm.