 |
 |
 |
|
 |
|
 |
|
 |
|
 |
|
 |
 |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
 |
|
|
|
Contents
Angles
Angle Properties of straight lines
Angle Properties of Parallel Lines
|
Angles An angle is two different rays having the same end point. In the figure below, the point A is called the vertex of the angle. AB and AC are called the sides or arms of the angle. We name this angle as angle BAC or angle CAB. We can write it in two ways: BĀC or BAC.
Another way of indicating an angle is shown below, where one letter of the alphabet is used. This angle is written as . There are three types of angles: 1. An acute angle is less than 90°. 2. An obtuse angle is greater than 90° but smaller than 180°. 3. A reflex angle is greater than 180° but less than 360°.
Two angles are said to be supplementary if their sum is 180°. So angles 165° and 15° are supplementary angles.
Two angles are said to be complementary if their sum is 90°.
|
