Angles
by Ender Raj

1. Right angle
1.1. 2 rays are perpendicular
1.2. Complementary
1.2.1. Sum of two angles equal to 90°
1.3. 90°
2. Parallel lines and transversal
2.1. Parallel lines
2.2. Non parallel lines
2.3. Transversal
2.3.1. Pairs of corresponding angles are equal to each other , then the pair of line are parallel
2.3.2. Sum of interior angles that the sum if interior angles on the same side of the transversal is supplementary, then the pair of lines are parallel.
2.3.3. Pair of alternate interior angles are equal to each other, then the pair of lines are parallel.
3. 2 line Segment
3.1. All angles are supplementary and adjacent
3.1.1. All angle equal to 360°
3.2. Only 2 adjacent/ supplementary angles equal to 180°
3.2.1. Known as straight angles .
3.2.2. To find other angle measurement, Subtract 180° - given angle
3.3. Vertical angles
3.3.1. Always equal
4. Adjacent angles
4.1. Share same ray
4.1.1. Means ' next to '
5. Semicircle
5.1. 180°
5.2. Supplementary
5.2.1. Sum of 2 angles equal to 180°
5.2.2. When adjacent to each other, they form a straight line