Curated OER
ndirect Measurement Technique: Using Trigonometric Ratios
Ninth graders find the height of an object that would be difficult or impossible to measure directly. They construct and use a Clinometer to measure the angle of elevation (or depression). Students create a sketch of the measurement...
Curated OER
Using Polynomials To Find Perimeter
Fifth graders engage in the solving of a real life application problem using the concept of calculating perimeter. They apply the operations of calculating with the polynomials for finding the perimeter of triangles,quadrilaterals, and...
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...
Cuemath
Cuemath: Area of a Circle
This mini-lesson explores the area of a circle. Provides a definition, examples, and practice questions with answers.
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.
OER Commons
Oer Commons: Area of a Circle
Seventh graders will compare the formula for the area of a regular polygon to discover the formula for the area of a circle.
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.
Purple Math
Purplemath: Sectors, Areas, and Arcs
Explains formulas for areas of sectors of circles and lengths of arcs. Demonstrates how to use the formulas in each of degrees and radians.
Illustrative Mathematics
Illustrative Mathematics: 7.g Eight Circles
In this lesson plan, 7th graders use their knowledge of formulas to determine the area and circumference of a circle.
PBS
Pbs Learning Media: Formulas: Targeted Math Instruction
At the end of this lesson plan about formulas, students will be able to identify and apply the correct formula for a given situation, solve for any unknown component of the formulas for perimeter, circumference, and area of regular and...
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.