Question

Triangle MNO has its vertices at the following coordinates:M(2, 2) N(-1,3) O(1,5)Give the coordinates of the image triangle M'N'O' after a 90° counterclockwise rotation about the origin.

Answer 1

The counter clockwise rotation of any point X(x,y) about origin results in change of coordinates as,

`X(x,y)\rightarrow X^(\prime)(-y,x)`

Determine the coordinates of the vertices of the triangle M'N'O'.

`M(2,2)\rightarrow M^(\prime)(-2,2)`
`N(-1,3)\rightarrow(-3,-1)`
`O(1,5)\rightarrow(-5,1)`

So coordinates of triangle M'N'O' are;

M'(-2,2)

N'(-3,-1)

O'(-5,1)