Flip/Rotate Tab

Angle: Enter a "± degree" value, then hit "set" to rotate selected vertices accordingly.

Rotate 90º: Rotates all vertices (whether selected or not) 90º counter clockwise.

Flip Horizontally: Flips all vertices (whether selected or not) horizontally, right to left.

Flip Vertically: Flips all vertices (whether selected or not) vertically, top to bottom.

Selected Vertices Only: Only preselected vertices will flip or rotate when checked.