Draw triangle XYZ with vertices X(1, 2), Y(0, 5), and Z(-8, 0).

Question

Graph triangle XYZ and its image after a 270 degree rotation about the origin. Name the coordinates of each vertex of the image.

Answer 1

Cartesian Coordinate system uses +x to the right and +y is up.  Points are written in (x,y) form.

 

Once rotated 270° (0° is the +x axis and go counterclockwise), this makes:

   what was the +x axis become the -y axis;

   and what was the +y axis becomes the +x axis, and

   what was the -x axis becomes the +y axis, and

   what was the -y axis becomes the -x axis.

 

The point X(1,2) gets the new coordinates of X^'(2,-1).

The point Y(0,5) gets the new coordinates of Y^'(5.0).

The point Z(-8,0) gets the new coordinates of Z^'(0,8).