Rotate a point about the origin by $\theta$ (#413)

Rotate a point about the origin by $\theta$ (#413)

Apply (x′,y′)=(xcos⁡θ−ysin⁡θ, xsin⁡θ+ycos⁡θ)(x',y') = (x\cos\theta - y\sin\theta,\ x\sin\theta + y\cos\theta).