Question

$△ABC$ is enlarged, to the point $O$ as the centre of enlargement, and the scale factor is $3$. Find $OA$, if $O{A}^{\prime }=6$ $cm$.

Answer 1

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

$\therefore 3\ast OA=O{A}^{\prime }$

$\because O{A}^{\prime }=6$

$⟹OA=\frac{6}{3}=2cm$