Kahn Academy
by Matthew H
1. Protractor
1.1. Virtual Protractor
1.2. Line Line up with Zero on protractor
2. Measuring Angles
2.1. Obtuse Angle
2.1.1. More than 90 degrees
2.2. Acute Angle
2.2.1. Less than 90 degrees
2.3. Right Angle
2.3.1. Exactly 90 degrees
3. Complementary And Supplementary
3.1. Adjacent
3.1.1. Shares at least one line or ray
3.1.2. Complementary
3.1.2.1. Two angles that add up to 90 degrees
3.1.3. Supplementary
3.1.3.1. Two angles that ad up to 180 degrees