Lines and Angles

Lines and angles are the fundamental terms in geometry that lay the groundwork for the topic. A line is a series of closely spaced dots that indefinitely span two directions. It just has 1 D, which is the length. A line can be thought of as a horizontal mark made on a piece of paper. A figure formed by two rays meeting at the same terminal is known as an angle. The protractor is used to measure them in angle (degrees). Lines and angles are present in all geometry shapes. In this session, we’ll study more about the many sorts of lines and angles.

Definition Of Lines and Angles

The concept of lines was developed by ancient mathematicians to depict straight objects with no width or depth. An angle can be defined as the shape formed by the intersection of 2 line segments, lines, or rays. While lines are easier to understand, an angle is a shape formed by the intersection of two-line segments, lines, or rays. The angle is formed when 2 rays cross each other in the same plane.

Lines

A line is a one-dimensional figure with no breadth that spans in both directions indefinitely. It is made up of an unlimited number of closely spaced points. The line is called a breadthless length by Euclid. It is represented on a cartesian plane by the linear equation ax + by = c.

Rays

Rays are lines that have one end that is the starting point and the other end that goes to infinity. They extend in one direction and don’t come to an end. An angle is formed when two rays are linked end to end. They are portrayed as AB

Line Segment

A line segment can be defined as the line with two endpoints. A line segment’s length can be calculated and written as PQ

Angles

An angle is formed when two rays intersect at a spot. Angles are commonly expressed in degrees and are symbolised by ◦ (the degree symbol), which is a measure of rotation. The symbol can be use be as an angle is and it can have a value of 0° to 360°.

Types of Lines and Angles

In geometry, there are various sorts of lines and angles. Let’s start by learning about the various types of lines.

Different Types of Lines 

Lines can be categorized into many kinds based on their characteristics. The many types of lines are shown in the table below.

1. Horizontal Line
2. Vertical Line
3. Parallel Line
4. Perpendicular Line
5. Transversal Line

1. Horizontal Line

A horizontal line is a straight line that extends from left to right or right to left in the coordinate plane and is parallel to the x-axis. The horizontal line is a straight line with an intercept solely on the y-axis and not on the x-axis.

2. Vertical Line

The vertical line is perpendicular to the surface or another line that forms the foundation. Vertical lines in coordinate geometry are parallel to the y-axis and often perpendicular to horizontal lines.

3. Parallel Line

Parallel lines are formed when two straight lines move parallel to each other and maintain a constant distance between them up to infinity. Parallel lines symbolise by ||.

4. Perpendicular Line

Perpendicular lines are formed when two lines intersect at an angle of 90°. The symbol are used to represent perpendicular lines. Here CD is the perpendicular Line.

5. Transversal Line

A transversal line is defined as a line that intersects two other lines at separate locations.

Angles of various types

Angles can be classified into various sorts based on their dimensions. Angles are classified into six categories:

1. An Acute angle can be defined as a measurement of an angle that is less than 90°.

1. Obtuse angle: An obtuse angle is defined as a measurement of an angle that is more than

 90° but less than 180 °.

1. Right angle is one in which the measure of an angle is exactly equal to 90 °.

1. Straight angle: A straight angle is defined as an angle with a measure of 180 °.

1. Reflex angle is defined as an angle that is higher than 180° but less than 360 °.
2. Complete angle: A complete angle is defined as an angle with a measurement of 360°.

Angles and Lines’ Properties

As we’ve seen, there are various types of lines and angles, each with its own set of characteristics. There are, however, some fundamental features of lines and angles that can be explored.

Lines’ Characteristics

• Lines are made up of an endless number of points that are near each other.
• It go on forever in both directions.
• It have no depth or thickness and are one-dimensional.

Angles’ Characteristics

• A geometrical figure created when two lines intersect in the same plane is called an angle.
• The lines that make up an angle are known as its arms (sides), and the place where they meet is known as the vertex.

Conclusion

• A few pointers to keep in mind when studying lines and angles are as follows:
• Angles and lines are present in all geometric shapes.
• A line is a one-dimensional shape with no width that stretches infinitely in both directions.
• These are the lines that start at one end and go to infinity at the other.
• Angles are formed with these. 
• When two rays intersect at a point, an angle is made.