Если луч OC проходит между сторонами угла AOB, то:

• \(\angle\) AOC + \(\angle\) BOC = \(\angle\) AOB.
• \(\angle\) AOC = \(\angle\) BOC.
• \(\angle\) AOB + \(\angle\) BOC = \(\angle\) AOC.
• \(\angle\) AOC + \(\angle\) AOB = \(\angle\) BOC.