BASIC CONCEPTS OF GEOMETRY
Figure 2 - 360o Angle
Depending on the rotation of a ray, an angle can be classified as right, straight, acute, obtuse, or
reflex. These angles are defined as follows:
Right Angle - angle with a ray separated by 90°.
Figure 3 Right Angle
Straight Angle - angle with a ray separated by 180° to form a straight line.
Figure 4 Straight Angle