Texas Instruments
Texas Instruments: Conics: Circles
In this study of conics, students will examine the derivation of equations for circles. There are two general equations for circles. The first is a circle whose center is at the origin, while the second is a circle whose center is not at...
McGraw Hill
Glencoe Mathematics: Online Study Tool: Self Check Quiz on Circles
The online assessment exhibits knowledge of advanced mathematical concepts in Trigonometry. The questions evaluate students on the topic of circles.
Purple Math
Purplemath: Completing the Square: Circle Equations
This tutorial works through two examples step by step that shows how to complete the square for finding the center and radius of a circle.
![Top Science: Pi Graph [Pdf] Unknown Type](https://d15y2dacu3jp90.cloudfront.net/images/attachment_defaults/resource/large/FPO-knovation.png "Top Science: Pi Graph [Pdf] Unknown Type")
TOPS Learning Systems
Top Science: Pi Graph [Pdf]
An activity where students explore and graph the relationship between the diameter and the circumference of a circle.
Purple Math
Purplemath: Conics: An Overview
Introduces the basics of conics in algebra, including a flow-chart for determining which sort of conic is represented by a given equation.
Walter Fendt
Walter Fendt: Apps on Mathematics
Apps for Arithmetic, Plane Geometry, and other Geometry concepts are provided.
Math Planet
Math Planet: Geometry: Parallelogram, Triangles Etc
Resource examines the area of geometric solids through examples and a video lesson. [0:39]
Khan Academy
Khan Academy: Area and Circumference of Parts of Circles
In this exercise, students practice find the area and circumference, of parts of circles. Students receive immediate feedback and have the opportunity to get hints and try questions repeatedly.
Illustrative Mathematics
Illustrative Mathematics: 4.g Lines of Symmetry for Circles
Mr. Watkins asked his students to draw a line of symmetry for a circle with center $O$ pictured below: Aligns with 4.G.A.3.
University of St. Andrews (UK)
University of St. Andrews: James Gregory
This site, which is provided for by the University of St. Andrews, contains information on the mathematician Gregory and his accomplishments.
Illustrative Mathematics
Illustrative Mathematics: 8.g Circle Sandwich
Eighth graders are presented with a drawing of a large square inscribed by a circle which is itself inscribed by a second square. They are asked to find the area of the circle outside the smaller square and compare it to the area of the...
CK-12 Foundation
Ck 12: Elem Math: Identifying Rectangles, Squares, Circles, and Triangles
[Free Registration/Login may be required to access all resource tools.] The video discusses a brief overview of circles, rectangles, squares, and triangles and helps students determine which shape is shown and why. The video is followed...
Visual Fractions
Visual Fractions: Add Fractions With Number Line or Circle Models
This site is provided for by Visual Fractions. Add mixed numbers with like denominators using circles. Click on the "Explain" button to understand the answer.
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.
CK-12 Foundation
Ck 12: Geometry: Circle Circumference
[Free Registration/Login may be required to access all resource tools.] In this lesson students find the circumference of a circle given the radius or the diameter. Students examine guided notes, review guided practice, watch...
CK-12 Foundation
Ck 12: Geometry: Circle Circumference
[Free Registration/Login may be required to access all resource tools.] In this lesson students find the circumference of a circle given its diameter or radius. Students examine guided notes, review guided practice, watch instructional...
CK-12 Foundation
Ck 12: Geometry: Chords in Circles
[Free Registration/Login may be required to access all resource tools.] This concept teaches students four theorems about chords and how to apply them. Students examine guided notes, review guided practice, watch instructional videos and...
CK-12 Foundation
Ck 12: Geometry: Chords in Circles
[Free Registration/Login may be required to access all resource tools.] In this lesson, students apply chord theorems. Students examine guided notes, review guided practice, watch instructional videos and attempt practice problems.
CK-12 Foundation
Ck 12: Geometry: Inscribed Quadrilaterals in Circles
[Free Registration/Login may be required to access all resource tools.] Learn about the Inscribed Quadrilateral Theorem and solve problems involving quadrilaterals inscribed in circles.
CK-12 Foundation
Ck 12: Geometry: Diameter or Radius of a Circle Given Circumference
[Free Registration/Login may be required to access all resource tools.] In this lesson, students find the radius, diameter, and circumference of different circles. Students examine guided notes, review guided practice, watch...
BBC
Bbc: Bitesize: Maths: 2 D Shapes
Learn about the properties of 2-D shapes: circles, triangles, polygons, and quadrilaterals. Includes information, video, and examples about each, with games and quizzes for reinforcement.
BBC
Bbc: Circumference and Area of a Circle
This is where you can pick up some valuable pointers on how to find the circumference and area of a circle. There is also information on how to find the perimeter and area of a semicircle. When you finish working your way through the...
CK-12 Foundation
Ck 12: Trigonometry: Area of a Sector
[Free Registration/Login may be required to access all resource tools.] Find the area of a sector of a circle.
CK-12 Foundation
Ck 12: Geometry: Angles Outside a Circle
[Free Registration/Login may be required to access all resource tools.] Solve problems containing angles outside a circle.