Two angles are Supplementary when they add up to 180 degrees (a Straight Angle).
They don't have to be next to each other, just so long as the total is 180 degrees.
Examples:
• 40° and 140° are supplementary angles.
• 60° and 120° are supplementary angles.
• 93° and 87° are supplementary angles.
Try dragging the points below: