This lesson focuses on the characteristics of a circle including similarity, radius, circumference, and Pi. It provides formulas to determine the area of a circle, calculating Pi, and learning exercises throughout.

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...

The circle is one of four different shapes which can be created using "slices" through a cone, a 3-dimensional solid that has a circular base joined to a single point (called the vertex) by a curved side. If you tilt a cone, you get an...

This lesson expands your knowledge about circles by learning about the segment of a circle, which will include its mathematical definition, area of the segment, types of segments in a circle, theorems based on a segment of a circle, and...

A comprehensive guide for learning all about chords of a circle with definitions, chords of a circle theorems, intersecting chords theorem, congruent circles, diameter, solved examples, and practice questions.

Given the center and radius of a circle, determine if a point is inside of the circle, on the circle, or outside of the circle.

A basic review of circles and how to calculate the circumference, radius, diameter, and area. Includes practice questions.

In this task, seven pennies are placed in a circle so that they are all touching one in the center and their neighbors. Students are asked to find as many rigid motions of the plane as they can which are symmetries of this configuration...

Here is a project that combines Computer Science and Mathematics. Prove a method for inscribing a circle within a triangle (as shown). You'll also learn how to create an interactive diagram to illustrate your proof, using an applet that...

Here is a project that combines Computer Science and Mathematics. Prove a method for circumscribing a circle about a triangle (as shown). You'll also learn how to create an interactive diagram to illustrate your proof, using an applet...

The arbelos is the white-shaded region between the three semicircles in the illustration at right. In this project, you'll prove an interesting method for determining the area of the arbelos.

Explains the basic concept of a square inscribed in a circle with step-by-step instructions and methods for solving specific problems on your own relating to this topic.

For this task, students are shown a unit circle in a plane and an angle measured from the x-axis. They must determine the coordinates of the line segment for the angle and answer a question about the sum of the coordinates. The purpose...

This a straightforward, but interesting, project in geometry. It is a good first proof to try on your own. You should be able to figure it out by yourself, and you'll gain insight into a basic property of circles.

Offers an explanation of what a geometric construction is and what some of the tools are that are used for it, including the traditional straightedge and compass. The site explains how to construct various polygons inscribed within a...

You have been hired by the owner of a local ice cream parlor to assist in his company's new venture. The company will soon sell its ice cream cones in the freezer section of local grocery stores. The manufacturing process requires that...

The interactive tutorial examines the properties and formulas of regular polygons, inscribed circles, and circumscribed circles.

This site, which is provided for by the University of St. Andrews, contains information on the mathematician Gregory and his accomplishments.

Mini-lesson takes a look at the definition and shape of a cylinder, cylinder formula, cylinder volume, and cylinder surface area. Try your hand at the cylinder surface area calculator and interactive questions for better understanding.

Solve two challenging problems that apply properties of tangents to find the radius of a circle with a tangent.

Learn all about arc length. This lesson targets what is arc length and the different formulas used to calculate it. Check-out the interactive simulations to know more about the lesson and try your hand at solving a few interesting...

This University of St. Andrews site contains information on the life of Heron as well as his accomplishments.

This University of St. Andrews site contains biographical information and findings of Christiaan Huygens.

This fourth-grade geometry lesson teaches the definitions for a line, ray, angle, acute angle, right angle, and obtuse angle. We also study how the size of the angle is ONLY determined by how much it has "opened" as compared to the whole...