Student Tutorial: Geometry Basics: Regular Polygons


Learn about regular polygons. For this tutorial you'll be using the Desmos Geometry Tools, which are free: Watch the video and follow along using the Desmos tools.

Click the arrows on the bottom to get started

Math Clip Art: Student Tutorial Title Page

Polygon. A closed figure on a plane made up of line segments, called sides, that meet at points called vertices. A polygon has a minimum of three sides.

Regular Polygon. A polygon with congruent sides and congruent interior angles.

Regular Polygons Title Card

A polygon is a closed figure with a distinct number of straight sides.

A regular polygon has congruent sides and congruent angles.

A regular triangle has 60° angles and three congruent sides.

Constructing a Regular Triangle

Step 1. Construct a circle.

Step 2. Draw a line through the center.

Step 3. Construct a semi-circle.

Step 4. Highlight the centers.

Step 5. Highlight the points in red.

Step 6. Construct the triangle shown.

Step 7. Note the congruent sides in the triangle.

Step 8. Note the equilateral triangle.

Step 9. Note the other equilateral triangle.

Step 10. Note the central angle and intercepted arc.

Step 11. Note the resulting 60° inscribed angle.

Step 12. Note the inscribed triangle is equilateral.

Step 13. This is the resulting regular polygon.