How to find the degree measure of an angle?

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How to find the degree measure of an angle?

For many in school, geometry is the real thing.test. One of the basic geometric figures is the angle. By this concept we mean two rays that originate at one point. To measure the value (magnitude) of the angle, degrees or radians are used. How to find the degree measure of the angle, you will learn from our article.

Types of angles

Let's say we have a corner. If we decompose it into a straight line, then its value will be equal to 180 degrees. Such an angle is called unfolded, and one-third consider 1/180 its part.

In addition to the developed angle, there are also sharp(less than 90 degrees), obtuse (more than 90 degrees) and straight (equal to 90 degrees) angles. These terms are used to characterize the magnitude of the degree angle measure.

Angle measurement

The value of the angle is measured with a protractor. This is a special device, on which the semicircle is already divided into 180 parts. Attach the protractor to the corner so that one side of the corner coincides with the bottom of the protractor. The second beam must cross the arch of the protractor. If this does not happen, remove the protractor and use a ruler to extend the beam. If the angle "opens" to the right from the top, read its value on the upper scale, if the left - on the bottom.

In the SI system it is customary to measure the angle inradians, not in degrees. In the deployed corner, only 3.14 radians are placed, so this value is inconvenient and practically not used in practice. That's why you need to know how to translate radians into degrees. For this, there is the formula:

• Degrees = radians / π × 180

For example, the angle is 1.6 radians. We translate into degrees: 1,6 / 3,14 * 180 = 92

Angle Properties

Now you know how to measure and recalculate degree measures of angles. But for solving problems it is necessary to know the properties of the angles. To date, the following axioms are formulated:

• Any angle can be expressed in degrees less than zero. The amount of the deployed angle is 360.
• If the angle is from several angles, its degree measure is the sum of all the angles.
• In a given half-plane, from any ray, it is possible to construct an angle of a given magnitude less than 180 degrees, with only one angle.
• The values ​​of equal angles are the same.
• To add two corners, we need to add their values.

Understanding these rules and the ability to measure angles is the key to a successful study of geometry.