Question

What are the coordinates of the image of D'E'F'G' after a rotation of 90º counterclockwise? The coordinates of the pre-image DEFG are D(2,0) E(2,2) F(5,2) G(5,1)

Answer 1

Given:

The coordinates of the pre-image DEFG are D(2,0) E(2,2), F(5,2), G(5,1).

To find:

The coordinates of the image of D'E'F'G' after a rotation of 90º counterclockwise.

Solution:

If a figure is rotated 90º counterclockwise, then

`(x,y)\to (-y,x)`

Using this rule, we get

`D(2,0)\to D'(0,2)`

`E(2,2)\to E'(-2,2)`

`F(5,2)\to F'(-2,5)`

`G(5,1)\to G'(-1,5)`

Therefore, the coordinates of the image of D'E'F'G' after a rotation of 90º counterclockwise are D'(0,2), E'(-2,2), F'(-2,5) and G'(-1,5).