Multiply the coordinates of the preimage by the scale factor k to get the image.
Practice makes perfect
To dilate the figure, we will start by graphing â–ł PQR. We have been given the points P(2,2), Q(4,4), and R(8,2).
We will now form the triangle by drawing segments between the points.
To find the coordinates of the image, we should use the coordinate rule for dilation. The rule tells us that we should multiply the coordinates of the preimages with the scale factor k.
ccccc
(x,y) &→& (1/2x,1/2y) &→& (x',y') [1em]
P(2,2) &→& (1/2(2),1/2(2)) &→& P'(1,1) [1em]
Q(4,4) &→& (1/2(4),1/2(4)) &→& Q'(2,2) [1em]
R(8,2) &→& (1/2(8),1/2(2)) &→&R'(4,1) [1em]
Now that we've calculated the points for the image, we can graph them in the same coordinate system as the preimage.
Our last step is to draw segments between the points P', Q', and R' to form the image.
