Defining an Angle
In geometry, an angle is the figure formed by two rays sharing a common endpoint. This common point is called the vertex, and the two rays are called the sides or arms of the angle. An angle represents the amount of rotation between its two sides.
Section 2: The Components of an Angle
Every angle consists of three main parts. The 'vertex' is the corner point where the two rays meet. The 'rays' are the two straight lines that extend outward from the vertex. The 'angle measure' is the amount of turn, typically measured in degrees (°), between the two rays.
Section 3: A Practical Example
Imagine the hands of a clock. The center of the clock where the hands are joined is the vertex. The hour hand and the minute hand are the two rays. The space between them forms an angle. For instance, at 3:00, the hands form a 90-degree angle, also known as a right angle.
Section 4: Importance and Measurement
Angles are fundamental to construction, architecture, engineering, and physics. They are measured using a tool called a protractor. Understanding angles is essential for creating shapes, navigating, and calculating trajectories and forces.