Please help me. I don't know how to do this without drawing and tracing. That is very slow. This is middle school math. Please don't use sin and cos. Please expain this for me. :confused: Thank you.

Draw triangle LMN with vertices L(2, -1), M(6, -2) and N (4, 2). Find the coodinates of the vertices after a counterclockwise 90 degree rotation about the origin and about each of the point L, M and N.