BBC
Bbc: Bitesize Review Circle Introduction
Do you need to learn about Pi, circumference, or the area of a circle or just have a quick refresher about them? This British web site will take you through the basics and offers a quick on-line test to help you check your understanding.
Texas Education Agency
Texas Gateway: Determining Area: Sectors of Circles
Students will use proportional reasoning to develop formulas to determine the area of sectors of circles. Students will then solve problems involving the area of sectors of circles.
Texas Education Agency
Texas Gateway: Determining Area: Regular Polygons and Circles
The student will apply the formula for the area of regular polygons to solve problems.
Khan Academy
Khan Academy: Area of Parts of Circles
Practice problems finding area of parts of circles.
Khan Academy
Khan Academy: Problem Solving With Area and Circumference of Circles
In this exercise, students practice problem solving the area and circumference of circles. Students receive immediate feedback and have the opportunity to get hints and try questions repeatedly.
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...
Other
Nearpod: Circles & Pi
In this lesson, 7th graders will learn vocabulary associated with circles and use formulas to find the area and circumference of circles.
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,...
National Council of Teachers of Mathematics
The Math Forum: Find the Area of the Shape!
Try to figure out the area of this challenging shape. In order to view the images, you will need to use JavaSketchpad.
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.
Google
Google for Education: Area of a Circle
Students learn to derive the formula for the area of a circle. They learn to relate a circle to a parallelogram and rectangle while learning the concept of infinity as they imagine slicing an circle into infinitesimally small slices.
Wolfram Research
Wolfram Math World: Heron's Formula
This site provides a detailed overview of Heron's Formula. Content includes a definition, example, and formula.
Khan Academy
Khan Academy: Area and Circumference of Circles Challenge
Try these challenge problems involving area and circumference.
Khan Academy
Khan Academy: Circumference of a Circle
Practice finding the circumference of a circle.
Khan Academy
Khan Academy: Circumference of Parts of Circles
Practice finding circumference of parts of circles.
Sophia Learning
Sophia: Finding a Formula for the Surface Area of a Cone
This video tutorial demonstrates how to find the formula for the surface area of a cone.
Other
Nearpod: Circles: Area and Circumference
In this lesson on circles, 7th graders will learn how to find the area and circumference of circles, semicircles, and compound shapes using formulas.
Texas Instruments
Texas Instruments: Area Formulas App
Students review the definition and area formula for the rectangle, square, parallelogram, triangle, trapezoid, and circle.
Texas Instruments
Texas Instruments: Getting Started With Area Formulas App
Calculate the Area of a Trapezoid This Concept Handheld Software Application reviews the definition and area formula for the rectangle, square, parallelogram, triangle, trapezoid, and circle.
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...
Texas Instruments
Texas Instruments: Arc Length and Area of Sectors
This is an introduction to finding the arc length and area of sectors of circles. Students should have the formulas for Circumference and Area of circles.
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 calculate the area of circles and the area of sectors of circles by using given information and formulas. Students examine guided notes,...
Free Math Help
Free Math Help: Area Formulas
The resource consists of area formulas and diagrams for a square, rectangle, circle, triangle, and trapezoid.