line.line segment,ray,complementary/supplementary angles

1. https://www.khanacademy.org/math/basic-geo/basic-geo-lines/basic-geo-lines-rays-angles/v/lines-line-segments-and-rays
2. https://www.ixl.com/math/geometry/lines-line-segments-and-rays
3. A line goes without end in both directions.
   A ray has 1 endpoint and goes without end in 1 direction.
   A line segment has 2 endpoints.
4. https://www.mathsisfun.com/geometry/complementary-angles.html
5. http://study.com/academy/lesson/complementary-angles-definition-theorem-examples.html
6. https://www.mathsisfun.com/definitions/supplementary-angles.html
7. https://www.mathsisfun.com/definitions/complementary-angle.html
8. 1. • 
9. Adjacent angles are two angles that have a common vertex and a common side. The vertex of an angle is the endpoint of the rays that form the sides of the angle. When we say common vertex and common side, we mean that the vertex point and the side are shared by the two angles. Below is an example of adjacent angles:

http://study.com/academy/lesson/what-are-adjacent-angles-definition-examples.html

• https://www.mathsisfun.com/definitions/adjacent-angles.html
• https://www.mathsisfun.com/geometry/adjacent-angles.html
• 1. • 
• A linear pair is a pair of adjacent angles formed when two lines intersect. In the figure, 1 and 2 form a linear pair. So do 2 and 3, 3 and 4, and 1 and 4. The two angles of a linear pair are always supplementary, which means their measures add up to 180^o.
• http://study.com/academy/lesson/linear-pair-definition-theorem-example.html
• http://www.icoachmath.com/math_dictionary/linear_pair.html