Varsity Tutors
Varsity Tutors: Hotmath: Practice Problems: Circle Exercises
Twenty-five problems cover various circle activities. They are given with each step to the solution cleverly revealed one at a time. You can work each step of the problem then click the "View Solution" button to check each step of your...
ClassFlow
Class Flow: Circle Vocabulary
[Free Registration/Login Required] This lesson lets students identify, draw, and measure parts of a circle. The lesson compliments 5th grade Harcourt Math, Lesson 23.4. Activote assessment is included at the end of the lesson.
Science and Mathematics Initiative for Learning Enhancement (SMILE)
Smile: Diameter,circumference,radius & the Discovery of Pi
This site provides a good project for students to use to explore the circumference of a circle.
University of Cambridge
University of Cambridge: Nrich: Watching the Wheels Go `Round and `Round
Use the formula for the circumference of a circle to solve the challenge of this problem. The solution is available at this one page website.
Other
Research Pages: Circle Inversion Fractals
This site introduces the iteration of circle inversions and describes the associated properties.
ClassFlow
Class Flow: Goats and Monsters
[Free Registration/Login Required] Students explore methods to measure lengths of squares and radius of a circle in trying to keep a goat from escaping.
Khan Academy
Khan Academy: Praxis Core Math: Circles Lesson
A basic review of circles and how to calculate the circumference, radius, diameter, and area. Includes practice questions.
Texas Instruments
Texas Instruments: Going in Circles Inscribed Angles
This lesson has students discover properties of inscribed angles in a circle. Students use the Geometer's Sketchpad application for the TI-89 to construct a circle and an inscribed angle.
Physics Aviary
Physics Aviary: Circular Friction Test Track
This lab is designed to have students find the relationships that affect the maximum speed a car can go around a turn. Students will be able to modify the tires, road surface, the mass of the car, radius of the turn and the initial speed...
Physics Aviary
Physics Aviary: Circular Acceleration
This program gives students a visual representation of why an object moving in a circle at constant speed is accelerating. This program will guide students through a method of calculating the circular acceleration based on the change in...
Illustrative Mathematics
Illustrative Mathematics: G C Right Triangles Inscribed in Circles I
This task provides a good opportunity to use isosceles triangles and their properties to show an interesting and important result about triangles inscribed in a circle with one side of the triangle a diameter. The fact that these...
Physics Aviary
Physics Aviary: Circular Force Lab
This lab is designed to have students find the relationships that affect the force required to keep an object moving in a circle. Students will be able to modify the mass of the object, the speed of the object and the size of the circle...
Physics Aviary
Physics Aviary: Classic Circular Force Lab
This lab is designed to examine the relationships between the force, mass, and radius of an object moving in a circular path and the velocity it must maintain to stay in that circular path. This lab is an idealized version of the string...
Illustrative Mathematics
Illustrative Mathematics: G C Right Triangles Inscribed in Circles Ii
For this task, students analyze the characteristics of a right triangle that has two sides labeled with midpoints and show that the triangle is inscribed in a circle with a diameter the length of its hypotenuse. Aligns with G-C.A.2.
Physics Aviary
Physics Aviary: Circular Acceleration Lab
This lab is designed to examine the factors that affect the radial acceleration that is felt by a driver that is going around a turn. The acceleration sensor is located on the driver's side of the car. Students will be able to change the...
University of Georgia
University of Georgia: Inter Math: Triangle Inequality
This site has a description of the triangle inequality theorem along with a visual representation, and animation explaining the triangle inequality rule with the radii of circles at the segment endpoints. Links to related terms, more...
Free Math Help
Free Math Help: Completing the Square in Circle Equations
This discussion examines how to complete the square in circle equations. Students learn about the math concept through definitions and examples with detailed solutions.
CK-12 Foundation
Ck 12: Geometry: Pi
[Free Registration/Login may be required to access all resource tools.] Identify pi as the ratio of a circle's diameter to a circle's circumference.
CK-12 Foundation
Ck 12: Area of Sectors and Segments: Pacman Area
[Free Registration/Login Required] Students are to determine the area of the shaded region between two radii. Click challenge me to answer practice questions and click learn more to watch a video.
Illustrative Mathematics
Illustrative Mathematics: G Gpe Slopes and Circles
The purpose of this task is to lead young scholars through an algebraic approach to a well-known result from classical geometry, namely, that a point X is on the circle of diameter AB whenever angle AXB is a right angle. This consists of...
National Council of Teachers of Mathematics
The Math Forum: Circles
Various forms of equations of circles are presented at the Math Forum: center-radius form, general form, diameter form, three-point form, and parametric form.
ClassFlow
Class Flow: Circles Geometry
[Free Registration/Login Required] Students identify segments and lines related to circles and the properties of a tangent to a circle.
Texas Instruments
Texas Instruments: Exploring Geometric Probability Using Ti Navigator
In this activity students will contribute a set of random points to a graph of a circle of radius 1 inscribed in a square. They will estimate the area of the circle using geometric probability.
CK-12 Foundation
Ck 12: Circumference: Ancient Stonehenge Math Mysteries
[Free Registration/Login Required] Students change the length of a radius to explore the circumference of a circle. Click challenge me to answer practice questions and click learn more to watch a video.