Interactive Mathematics: Angles Degrees and Radians

Given a pair of parallel lines and a triangle in between, geometers prove that the sum of the interior angles is 180 degrees. This quick quest can be used as a pop quiz or exit ticket for your geometry class.

Help 9th graders identify lines, points, rays, and planes in geometry. They  practice identifying, measuring, and drawing angles of different degrees. This is a fundamental lesson to help students learn the building blocks of geometry.

Measure angles is easy as pi. Pupils review special right triangles to find exact values for trigonometric functions. Scholars learn about radians and how they connect to measurements in degrees. They find exact and approximate values of...

How do degrees relate to radians? The interactive allows pupils to manipulate the size of an angle in a unit circle to help see that relationship. Users determine the radian measure for given degree measures of angles, realizing the...

How are arc lengths and radians related? An interactive resource demonstrates the relationship as pupils create arc lengths in a unit circle and compare them to the angle measurements. Questions ask individuals to build upon this...

Forget hours, divide the day into radians instead. Class members convert the angles in a pie chart of daily activities into radian measures. They add angle measures for multiple activities then determine a relationship between the radian...

It's 3:30, what radian is it? Pupils create clock angles on a clock and determine the radian measure to the minute hand. They then use a conversion factor to convert from one measurement to another.

Serve up angle measurements on paper plates. Pupils use paper plates and paper-folding techniques to create a unit circle with conversions for special angles. Using their plates, learners explore the relationship between angle...

Students label key points on the unit circle in both radians and degrees. They count their way around the circle in 30-degree increments, and then again in increments of radians. Finally, students go through a similar process for angles...

Rather than dividing a circle into some number of segments (like 360 degrees), mathematicians often prefer to measure angles using the circumference of a unit circle - a circle with radius 1. This way of measuring angles is called...