new co ordinates of a rotated shape

[Happyface]

Please help!!!
best way to explain this:-
how to tell what are the new co ordinates of a shape tjat has been rotated, by a certain angle about a certain point...
we are sitting CEM test if that's relevant.
we,ve looked at videos but all use tracing papers etc so no good.
thanks much in advance

[rejim2]

The rule for a rotation by 90° about the origin is (x,y) to (-y,x)
The rule for a rotation by 180° about the origin is (x,y) to (-x, -y)
The rule for a rotation by 270° about the origin is (x,y) to (y, -x)

Hope it helps!!