7th grade geometry/angles review

A right angle is an angle that measures exactly 90 degrees.

Adjacent angles are two angles that share a common side and a common vertex but do not overlap.

The sum of the interior angles in a triangle is always 180 degrees.

Two angles are complementary if their measures add up to 90 degrees. To find the unknown angle, subtract the known angle from 90 degrees.

The measure of an exterior angle is equal to the sum of the measures of the two non-adjacent interior angles.

Vertical angles are the angles opposite each other when two lines intersect. They are always equal in measure.

If two angles form a linear pair, their measures add up to 180 degrees. Use the equation: angle1 + angle2 = 180.

Complementary angles are two angles whose measures add up to 90 degrees.

Supplementary angles are two angles whose measures add up to 180 degrees.

The complement of angle A is 45 degrees, so its complement measures 45 degrees (90 - 45 = 45).