Oswego City School District
Regents Exam Prep Center: Circles: Area of Sectors and Segments
Material to supplement classroom instruction on sectors and segments of circles. Find guidelines on how to find the area of sectors and segments, as well as a multiple-choice quiz, and an activity idea called "Sectors and Pizza."
Mathigon
Mathigon: Geometry: Circle and Pi: Introduction
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.
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...
Cuemath
Cuemath: Circles
Explore everything about circles. Learn various parts of a circle like a diameter, radius, circumference, circles chord, tangent circles, major arc, segment, sector, and discover other interesting aspects of it. Try your hand at solving...
National Council of Teachers of Mathematics
The Math Forum: Elementary Geometry Circles
The Math Forum offers an archive of question and answer sessions on circles and how they relate to geometry.
Maths Challenge
Maths challenge.net: Lunes
A "three star" geometry problem where some experience of math problem solving skills and knowledge of circles is recommended to solve this lunes (parts of a circles) area problem
Oswego City School District
Regents Exam Prep Center: Circles, Segments, and Area
A wealth of resources to supplement instruction on parts of the circle. Find lessons describing chords, tangents, secants, and segments, as well as related practice quizzes and classroom activities.
Cuemath
Cuemath: Area of a Circle
This mini-lesson explores the area of a circle. Provides a definition, examples, and practice questions with answers.
Khan Academy
Khan Academy: Area of a Circle
Find the area of a circle given its radius, diameter, or circumference. Students receive immediate feedback and have the opportunity to try questions repeatedly, watch a video or receive hints.
CK-12 Foundation
Ck 12: Geometry: Circumference and Arc Length Study Guide
This study guide on circumference and arc length covers key vocabulary, the parts of a circle, and formulas for circumference, area, and arc length. It is available for download with free registration.
Khan Academy
Khan Academy: Area and Parts of Circles
Practice finding the area or circumference of part of a circle. Students receive immediate feedback and have the opportunity to try questions repeatedly, watch a video or receive hints.
Analyze Math
Analyze Math: Overlapping Circles Problem
Try this problem - find the area of the overlapping region of two overlapping circles. You need to find the region of each segment, then add them up. This site gives the problem and a detailed written solution. Good problem for sharp...
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...
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,...
CK-12 Foundation
Ck 12: Examining Circles: Area of a Circle
[Free Registration/Login Required] Students use the radius and diameter to determine the area of a circle. Click challenge me to answer practice questions and click learn more to watch a video.
University of Waterloo (Canada)
University of Waterloo: Cemc: Math Circles: 3 D Geometry Ii [Pdf]
This worksheet provides a variety of 3D geometry questions requiring higher order thinking skills. Questions include; finding the surface area of a prism, surface area of pyramid, surface area of a sphere, and platonic solids.
Maths Challenge
Maths challenge.net: Semi Circle Lunes
A lune of a circle is defined and a problem of finding the area of two lunes is given.
Science Buddies
Science Buddies: Thinking in (Semi )Circles: The Area of the Arbelos
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.
Maths Challenge
Maths challenge.net: Rectangular Circles
An area problem involving finding the area of a rectangle and a circle. The problem may be made into a general proof as well.
Government of Alberta
Learn Alberta: Math Interactives: Exploring Surface Area, Volume, and Nets
Investigate the concepts of area, volume, 3D shapes, and nets using this interactive Learn Alberta math. The solid shapes focused on this exploration include rectangular and triangular prisms, rectangular and triangular pyramids,...
Mr. Martini's Classroom
Mr. Martini's Classroom: Circles Geometry Review
This resource provides two levels of multiple choice questions to review the parts of a circle as well as area and perimeter.
Cuemath
Cuemath: Segment of a Circle
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...
CK-12 Foundation
Ck 12: Geometry: Area of a Circle
[Free Registration/Login may be required to access all resource tools.] This concept teaches students how to calculate the area of a circle. Students examine guided notes, review guided practice, watch instructional videos and attempt...
CK-12 Foundation
Ck 12: Geometry: Area of a Circle
[Free Registration/Login may be required to access all resource tools.] In this lesson students find the area of a circle given its radius or diameter. Students examine guided notes, review guided practice, watch instructional videos and...