Lines and Angles

Lines

A line is a straight path that extends infinitely in both directions. There are different types of lines:

• Straight Line: A line that does not curve or bend.
• Ray: A line that has one endpoint and extends infinitely in one direction.
• Line Segment: A part of a line that has two endpoints.

Angles

An angle is formed when two rays share a common endpoint. The common endpoint is called the vertex of the angle. Angles are measured in degrees.

• Right Angle: An angle that measures 90 degrees.
• Straight Angle: An angle that measures 180 degrees.
• Acute Angle: An angle that measures less than 90 degrees.
• Obtuse Angle: An angle that measures more than 90 degrees but less than 180 degrees.

Types of Angles

There are various types of angles based on their measurements and relationships:

• Adjacent Angles: Two angles that share a common vertex and a common side, but do not overlap.
• Complementary Angles: Two angles whose measures add up to 90 degrees.
• Supplementary Angles: Two angles whose measures add up to 180 degrees.
• Vertical Angles: Two non-adjacent angles formed by the intersection of two lines. They are always congruent (have the same measure).

Study Guide

To study lines and angles, make sure to understand the following key concepts:

1. Identify different types of lines and their characteristics (straight line, ray, line segment).
2. Understand the properties of angles and how they are measured in degrees.
3. Recognize the different types of angles (right, straight, acute, obtuse) and their properties.
4. Learn about angle relationships such as adjacent, complementary, supplementary, and vertical angles.
5. Practice drawing and identifying various types of angles and lines in geometric figures.

[Lines And Angles] Related Worksheets and Study Guides:

• AnglesMathematics • Fifth Grade