Graph the image of the figure after a dilation with a scale factor of 13 centered at (1, −2) .

Use the polygon tool to graph the triangle by connecting all its vertices.

The graph points are (4,7),(-8,4),(-8,-2) I know how to dilate them, but it's centered at (1,-2) so I'm confused

sii1lver
Jan 5, 2018

#1**+1 **

The "formula" for finding the new points is as follows

New Point = [ Old Point - Dilation Center ] *Scale Factor + Dilation Center

Here's the first one.....you should be able to do the other three based on this....if not, let me know

Note that (a, b) - (c, d) = ( a - c , b - d) and (a , b) + (c , d) = (a + c , b + d)

Here's the dilation result for (4,7)

New Point = [ (4, 7) - ( 1, -2) ] * 13 + (1,-2)

= [ ( 3, 9) ] * 13 + (1,-2)

= (39, 117 ) + (1, -2)

= (40, 115)

CPhill
Jan 6, 2018