Group+B


 * Parallel Lines**

The picture on the left shows a pair of parallel lines. The picture on the right shows a pair of lines that are not parallel.


 * Definition: If a pair of lines are lined up next to each other and never intersect, then they are parallel lines.**




 * Definition: If the sum of two angle measures is 180 degrees, then the two angles are a pair of supplementary angles.**




 * Definition: If the sum of two angle measures is 90 degrees, then the angles are a pair of complementary angles.**