Varsity Tutors
Varsity Tutors: Hotmath: Practice Problems: Geometry in the Plane
Twenty-four problems presented on a variety of Plane Geometry topics. 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...
Mathigon
Mathigon: Geometry: Circle and Pi: Degrees and Radians
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...
CK-12 Foundation
Ck 12: Geometry: Circles in the Coordinate Plane
[Free Registration/Login may be required to access all resource tools.] This concept teaches students how to graph circles and find the standard equations of circles. Students examine guided notes, review guided practice, watch...
CK-12 Foundation
Ck 12: Geometry: Circles in the Coordinate Plane
[Free Registration/Login may be required to access all resource tools.] In this lesson students find the standard equation of a circle. Students examine guided notes, review guided practice, watch instructional videos and attempt...
Math2
Math2: Circles
This site has many useful formulas and examples relating to circles, including related definitions, circumference of a circle, area of a circle, length of a circular arc, area of a circular sector, equation of a circle in cartesian...
University of Saskatchewan (Canada)
University of Saskatchewan: Geometry
The University of Saskatchewan's Department of Mathematics and Statistics provides high school students with online tutorials and exercises on what they deem some of the most important topics in geometry: Triangles, and Circles and Other...
Khan Academy
Khan: Lesson 16: Part 2 Coordinate Geometry; Trigo and Radians; Complex Numbers
2 OF 2 FOR ADDITIONAL TOPICS IN MATH. Students will use the coordinate plane and equations of lines and circles to describe figures; create the equation of a circle given the figure or use the structure of a given equation to determine a...
Khan Academy
Khan Academy: Points Inside/outside/on a Circle
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. Students receive immediate feedback and have the opportunity to try questions repeatedly, watch a video or...
CK-12 Foundation
Ck 12: Geometry: Properties of a Circle Study Guide
[Free Registration/Login may be required to access all resource tools.] This study guide reviews the terminology for circles (tangent, arcs, central angles) and the equation for a circle.
CK-12 Foundation
Ck 12: Geometry: Segments From Secants and Tangents
[Free Registration/Login may be required to access all resource tools.] This concept teaches students to solve for missing segments created by a tangent line and a secant line intersecting outside a circle.
Khan Academy
Khan Academy: Points Inside/outside/on a Circle
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.
CK-12 Foundation
Ck 12: Elem Math: Classify Objects as Rectangles, Squares, Circles, or Triangles
[Free Registration/Login may be required to access all resource tools.] Students watch a video and attempt practice problems on classifying rectangles, squares, circles and triangles.
CK-12 Foundation
Ck 12: Elem Math: Identifying Rectangles Squares Circles and Triangles
[Free Registration/Login may be required to access all resource tools.] Students watch a video overview and attempt practice problems on identifying rectangles, squares, circles and triangles.
CK-12 Foundation
Ck 12: Circles in the Coordinate Plane
[Free Registration/Login Required] Students will move points on a circle to explore standard equations when given the radius and center. Click challenge me to answer practice problems and click learn more to watch a video.
CK-12 Foundation
Ck 12: Circles in the Coordinate Plane: Watering the Field
[Free Registration/Login Required] Students can move points in a circle to determine the standard equation from the raidus and center. Click challenge me to answer practice questions and click learn more to watch a video.
Common Core Sheets
Common Core Sheets: Geometry 8.g.3 Worksheets: Coordinate Plane
Worksheets provide practice with finding the area or circumference of a circle and answer keys are provided. You can even create your own worksheet or flashcards.
Illustrative Mathematics
Illustrative Mathematics: G Co Seven Circles Ii
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...
Oswego City School District
Regents Exam Prep Center: Area of Polygons and Circles
How would you find the area of a polygon or circle? Explore this concept with engaging activities at this test prep site. Here you will find detailed problem solving strategies with accompanying visuals, a reference table with formulas,...
Walter Fendt
Walter Fendt: Apps on Mathematics
Apps for Arithmetic, Plane Geometry, and other Geometry concepts are provided.
CK-12 Foundation
Ck 12: Interactive Geometry: 10.1 Conic Sections
The conic sections are the cross-sections of a double-napped cone. Depending on the angle of the plane with respect to the cone, a conic section may be a circle, an ellipse, a parabola, or a hyperbola.
Calculator Soup
Calculator Soup: Circle Calculator
Use this circle calculator to find the area, circumference, radius, or diameter of a circle. Given any one variable A, C, r or d of a circle you can calculate the other three unknowns.
Mangahigh
Mangahigh: Pyramid Panic: Basic Shapes to Advanced Geometry
Guide a mummy safely through the burial chambers of a pyramid as you solve length and area problems in basic to advanced geometry. There are four game zones that deal with circles and triangles, quadrilaterals, the Pythagorean Theorem,...
CK-12 Foundation
Ck 12: Geometry: Inscribed Angles in Circles
[Free Registration/Login may be required to access all resource tools.] Apply inscribed angle theorems.
CK-12 Foundation
Ck 12: Geometry: Segments From Secants
[Free Registration/Login may be required to access all resource tools.] Apply the Two Secants Segments Theorem.