Chapter 12.7, Problem 26E

To determine

To graph: draw triangle $DEF$ with vertices $D\left(4,3\right),E\left(6,3\right)\text{ and F}\left(5,1\right)$ and also find the coordinates of the vertices of the image after $90°$ counter clockwise rotation about the origin.

Explanation of Solution

Given information: the coordinates of triangles $DEF$ are as follows: $D\left(4,3\right),E\left(6,3\right)\text{ and F}\left(5,1\right)$

Graph: first draw triangle $DEF$ with vertices $D\left(4,3\right),E\left(6,3\right)\text{ and F}\left(5,1\right)$ then

Original	Image
$(x,y)$	$\left(4x,4y\right)$
$A(4,0)$	$P(16,0)$
$B(4,4)$	$Q(16,16)$
$C(-4,0)$	$R(-16,0)$

Finally draw a triangle $PQR$ , as shown below

Interpretation: Hence, the vertices of image after dilation are $P\left(16,0\right),Q\left(16,16\right)\text{ and R}\left(-16,0\right)$