Question

How to rotate a figure ${90}^{°}$ clockwise about a point?

Answer 1

Rotate a figure ${90}^{°}$ clockwise about a point :

When a point say $P(h,k)$ is rotated about origin $O$ through ${90}^{°}$ clockwise direction, the new position will be $P(k,-h)$

Since to rotate ${90}^{°}$ clockwise about a point, every point $\left(x,y\right)$ will rotate to $\left(y,-x\right)$

Hence, with change of coordinate from $P(h,k)$ to $P(k,-h)$ we can rotation a figure ${90}^{°}$ clockwise about a point.