+146 Point $B$ is the image of point $A$ under a dilation with center $O$. If $OB = 30$, and the scale factor of the dilation is $5$, then what is $OA$?
+1790 This question isn't hard at all, and only involves one key fact.
First, we HAVE to know the formula
Dilation Factor = Length of Image / Length of Pre-image
So, now, we just plug in some numbers and we are done!
Length of AB (image) = 30 units
\(5 = 30 / OA\\ OA = 30/5\\ OA = 6\)
So OA is basically just 6 units.
Thanks! :)
