Rotating texture in rhino on mac?

Hi people of the internet. I am running Rhino on a mac and found the place to rotate a texture, but the text is greyed out and will not let me change the rotation of the texture. What do i have to do to rotate the texture?

click on texture mapping custom its below material, then choose planar.
the quickest to rotate is to use 3 point.

Perfect. Thank you very much!