Description: Parallel lines crossing tranversel line.
Image copyright: My own creation, 2009, in Paint.
1. Transversal: A line that cross two or more other lines.
2. Angle: The amount of turning between two lines that meet at a common point.
3. Parallel: Lines that are the same distance apart.
4. Perpendicular: Two lines that intersect in at a 90º right angle.
5. Adjacent angle: Is next to.
6. Alternate exterior angle: An angle formed outside a polygon when one side is extended.
7. Alternate interior angle: An angle within a polygon.
8. Vertical angle: Pair of angles opposite each other, formed by the intersection of straight lines.
9. Acute angle: An angle that is less than 90 º.
10. Obtuse angle: An angle that is larger than 90 º.
11. Right angle: An angle that is 90 º.
Key:
Parallel: segment AB is parallel to segment CD
Vertical Angles: 1 & 3, 2 & 4, 5 & 7, 8 & 6
Adjacent Angle: 1 & 2, 1 & 4, 2 & 3, 3 & 4, 5 & 6, 5 & 8, 6 & 7, 7 & 8.
Transversal line: EF
Alternate Exterior Angle: 1 & 7, 4 & 6
Alternate Interior Angle: 2 & 8, 3 & 5
Acute Angle: 2, 4, 6, 8.
Obtuse Angle: 1, 3, 5, 7.
Right Angle: none