Interactive, free online geometry tool from GeoGebra: create triangles, circles, angles, transformations and much more!

Use the ANGLE tool to measure the 3 interior angles of the triangle shown. Also, use this tool to find and display the measure of the one interior angle (lower left). When you're done (or if your unsure of something), feel free to check by watching the quick silent screencast below the applet.

The Angle button allows you to draw an angle between 2 lines or 3 points.

Discover over 34 free and ready-to-use GeoGebra resources for grades 4-8 to learn and practice different types of angles. Improve your skills in drawing and measuring angles with a protractor.

Besides a protractor, Geogebra has its own embedded ANGLE measurement tool. Let's go ahead and use it as we start developing our common vocabulary terms. It is the top tool in this list of tools and looks like the following:

Using the "angle" tool, create an obtuse angle. Next, choose the "angle" tool and plot three points that create an angle greater than 90º but less than 180º. As you plot each point, hit "shift" with a capital letter to name the point.

You can use this tool to perform rotations of quadrilaterals around the origin in the coordinate plane. Be sure to try to perform the rotation manually at first, but then feel free to use this tool to check your work and visualize the rotation.

(Updated: 8 Sept 2016) Measure the angle using the protractor. Drag the protractor to appropriate position. Drag the red point to rotate it. Drag the green points or press the "Random" button to adjust the angle.

1) Using the POINT TOOL, mark point D on segment AB 2) Using the COMPASS TOOL, create a circle with radius AD and center point A 3) Using the POINT TOOL, mark point E where circle A intersects segment AC 4) Using the COMPASS TOOL, create a circle with the radius DE and center point D 2) Using the COMPASS TOOL, create a circle with the radius DE ...

Quickly Construct a Right Triangle With an Angle and a Side or Two Sides. Flip the triangle to your liking and choose which units to display.