Adjacent angles

In geometry, adjacent angles, often shortened as adj. ∠s, are angles that have a common ray coming out of the vertex going between two other rays, with no overlap of the regions "enclosed" by the two angles. In other words, they are angles that are side by side, or adjacent.

Complementary adjacent angles

A pair of angles is complementary if the sum of their measures is 90°.

A pair of angles is supplementary if the sum of their measures is 180°. Example angle A is 40° and angle B is 140° this is a supplementary angle An angle with a ray connected to a common point down the center. In geometry, two angles are adjacent angles if they share a common vertex and side, but have no common interior points.

External links

• Complementary Angles animated demonstration. With interactive applet
• Supplementary Angles animated demonstration. With interactive applet
• Angle definition pages with interactive applets that are also useful in a classroom setting. Math Open Reference