Fourth graders will discover the building blocks of geometry in this unit: points, lines, line segments and rays. Students will explore the properties of different shapes, including symmetry, parallel and perpendicular lines, and 900 angles. Students will apply their understanding as they learn to sort shapes based on these properties.
Representing data on graphs makes math visual and involves some creativity and design. Plotting data using fractional units takes their learning one step further. Also in this unit, students learn to measure using both traditional units (like inches, feet and yards) and metric units, and how to convert measurements within each system. The concept of measurement gets two dimensional when students explore measuring and working with angles.
Angles are an important concept in geometry and are used when working with shapes like circles and triangles. Once your child has mastered using angles, they are ready to start moving on to a higher level math subject, such as algebra. Help your student learn how to work with angles by looking at our different resources, or if your child is ready to move ahead, see how angles are used in triangles.
A Guide to Angles
Angles are used to measure how far something has turned. Below is a guide for getting started with angles.
Parts of an Angle
An angle is made up of two lines called arms. These arms are connected at one end to form a point called the vertex. The angle is then defined to be the amount of turn between each arm.
Types of Angles
Different angles have different names depending on their angle:
Acute: an angle that is less than 90 degrees
Right: an angle that is exactly 90 degrees
Obtuse: an angle that is greater than 90 degrees but less than 180 degrees
Straight: an angle that is exactly 180 degrees
Reflex: and angle that is greater than 180 degrees
When working with angles, there is also a difference between a positive and negative angle. A positive angle rotates counterclockwise, while a negative angle rotates clockwise.
In more complex math classes, students begin to learn how to determine if angles are congruent, or equal, and how to use angles in math classes like algebra and calculus. To help your student start their journey through angles, check the resources on this page, or move over to our geometry page to learn more about how angles are used in shapes.