A pair of angles are supplementary if their respective measures sum to 180 degrees.

If the two supplementary angles are adjacent (i.e. have a common vertex and share a side, but do not have any interior points in common) their non-shared sides form a line.

See also

• Complementary angles
• Angle

External links

• Animated demonstration - Interactive applet and explanation of the characteristics of supplementary angles.
• Supplementary Angles from Math Is Fun

Angle | Elementary geometry

Суплементни агли | Ángulos suplementarios | Suplementaj anguloj