Question

$△ABC$ is enlarged, about the point $O$ as the centre of enlargement, and the scale factor is $3$. Find $O{C}^{\prime }$, if $OC=21$ $cm$.

Answer 1

Every length related to $△ABC$ will be enlarged by $3$ to give corresponding increased lengths of $△A^{\prime }{B}^{\prime }{C}^{\prime }$

$\therefore 3\ast OC=O{C}^{\prime }$

$\because OC=21$

$⟹O{C}^{\prime }=3\times 21=63cm$