Revolution

Definition

A revolution is a complete or radical change in a situation or in the way things are done. In the context of angles, a revolution refers to the complete rotation of an angle around a fixed point, typically measured in degrees or radians.

5 Must Know Facts For Your Next Test

1. One complete revolution of an angle is equal to 360 degrees or $2\pi$ radians.
2. The measure of an angle in degrees is directly proportional to the length of the arc it subtends on a circle.
3. The measure of an angle in radians is equal to the ratio of the length of the arc it subtends to the radius of the circle.
4. Angles can be classified based on the number of revolutions they represent, such as acute, obtuse, and reflex angles.
5. Rotations and revolutions are fundamental concepts in the study of trigonometry and the behavior of periodic functions.

Review Questions

• Explain the relationship between the measure of an angle in degrees and the measure of the same angle in radians.
  • The measure of an angle in degrees is directly proportional to the measure of the same angle in radians. Specifically, one complete revolution of an angle is equal to 360 degrees or $2\pi$ radians. This means that the conversion between degrees and radians can be expressed as $\theta_{degrees} = \frac{360}{2\pi}\theta_{radians}$ or $\theta_{radians} = \frac{2\pi}{360}\theta_{degrees}$. Understanding this relationship is crucial for working with angles in various mathematical and scientific contexts.
• Describe how the measure of an angle in radians is related to the length of the arc it subtends on a circle.
  • The measure of an angle in radians is equal to the ratio of the length of the arc it subtends on a circle to the radius of the circle. This means that the radian measure of an angle is a dimensionless quantity that represents the fraction of the circumference of a circle that the angle occupies. This relationship allows for the direct connection between the geometric properties of a circle and the angular measurements used in trigonometry and other mathematical applications.
• Analyze how the classification of angles based on the number of revolutions they represent can be used to understand the behavior of periodic functions.
  • Angles can be classified as acute, obtuse, or reflex based on the number of revolutions they represent. This classification is closely tied to the behavior of periodic functions, such as sine and cosine, which repeat their values after a full revolution of 360 degrees or $2\pi$ radians. Understanding the relationship between angle classification and periodic function behavior allows for the analysis of the properties and characteristics of these functions, which are fundamental to many areas of mathematics and science, including the study of oscillations, waves, and circular motion.

Related terms

Angle: An angle is the figure formed by two rays, called the sides of the angle, that share a common endpoint called the vertex.

Radian: A radian is a unit of angular measurement that is defined as the angle subtended by an arc on a circle that is equal in length to the radius of the circle.

Degree: A degree is a unit of angular measurement that divides a full circle into 360 equal parts, with each part representing one degree.