Illuminations
Circumference and Areas of Circles
Middle and high schoolers listen to a scenario about a puppy and use the scenario to develop formulas in order to find the area of a circle. In this circumference lesson, pupils understand how to find the radius, diameter, area of a...
Curated OER
Area and Circumference of Circles
Learners view two PowerPoints and practice computing the area and circumference of circles. They must use given formulas to make their computations. The lesson includes links to both PowerPoints as well as a worksheet (with answer key).
National Research Center for Career and Technical Education
Transportation, Distribution, and Logistics: Tire and Wheel Assemblies
Is bigger really better? By the end of this lesson, learners will be able to apply formulas for computing the diameter of tires and wheel assemblies. Begin by showing a slide presentation that will review definitions for radius and...
Virginia Department of Education
Arc Length and Area of a Sector
What do skateboarding and baked goods have in common with math? You can use them to connect half-pipe ramps and cakes to arcs and sectors. Pupils compare the lengths of three different ramp options of a skate park. They calculate the...
Curated OER
Area and Circumference of Circles
Students calculate the area and circumference of a circle as the lesson is presented through an animated Microsoft PowerPoint presentation. They then complete a project to review the previous day's material.
EngageNY
Arcs and Chords
You've investigated relationships between chords, radii, and diameters—now it's time for arcs. Learners investigate relationships between arcs and chords. Learners then prove that congruent chords have congruent arcs, congruent arcs have...
Virginia Department of Education
Going the Distance
Estimate the value of one of the most famous irrational numbers. The hands-on instructional activity instructs classmates to measure the circumference and diameters of circles using yarn. The ratio of these quantities defines pi.
Illustrative Mathematics
Seven Circles III
A basic set-up leads to a surprisingly complex analysis in this variation on the question of surrounding a central circle with a ring of touching circles. Useful for putting trigonometric functions in a physical context, as well as...
EngageNY
Arc Length and Areas of Sectors
How do you find arc lengths and areas of sectors of circles? Young mathematicians investigate the relationship between the radius, central angle, and length of intercepted arc. They then learn how to determine the area of sectors of...
Curated OER
Circles-Diameter, Circumference, Radius and the Discovery of Pi
Seventh graders measure the diameter, circumference and radius of a circle and find pi using the diameter and circumference. For this geometry lesson, 7th graders work in groups to find the diameter, radius, and circumference of circles....
EduGAINs
Discovery of Pi
Serve up a slice of math for Pi Day! A combination of fun, hands-on lessons and helpful worksheets encourage learners to practice finding the radius, diameter, and circumference of different circles.
Virginia Department of Education
Angles, Arcs, and Segments in Circles
Investigate relationships between angles, arcs, and segments in circles. Pupils use geometry software to discover the relationships between angles, arcs, and segments associated with circles. Class members use similar triangles to...
Texas Instruments
Area of Circles
Students explore circles. In this algebra/geometry lesson, students discover the formula for the area of a circle, as they investigate the ratio of the area of a circle to the radius^2.
Curated OER
Circle Circus
Third graders find the radius and diameter of a bubble. In this radius and diameter instructional activity, 3rd graders create bubbles on their desk and find the radius and diameter of the bubble. Students work in partners to define...
EngageNY
The Area of a Circle
Introduce learners to two methods to estimate the formula for the area of a circle. The first method uses a sector of a circle to form a rectangle, and the other uses grids to estimate the area. The problems in the 18th segment of a...
Willow Tree
Area of Common Geometric Figures
Scholars can use area formulas, but can they apply what they know about area? The lesson challenges learners to think logically while practicing finding area of shapes such as rectangles, circles, parallelograms, triangles, and other...
Illustrative Mathematics
Right Triangles Inscribed in Circles II
So many times the characteristics of triangles are presented as a vocabulary-type of lesson, but in this activity they are key to unraveling a proof. A unique attack on proving that an inscribed angle that subtends a diameter must be a...
Illustrative Mathematics
Right Triangles Inscribed in Circles I
One of the basic properties of inscribed angles gets a triangle proof treatment in a short but detailed exercise. Leading directions take the learner through identifying characteristics of a circle and how they relate to angles and...
Curated OER
The Area of a Circle
Eighth graders find the circumference and diameter of several lids, show the relationship of the two measurements and derive the formula for finding the area of a circle. In this area of a circle lesson plan, 8th graders find...
Curated OER
Finding the Circumference and Area of a Circle
Sixth graders discover what circumference is. In this measurement lesson, 6th graders identify the radius and diameter of different circles. Students discover how to find the area of a circle using the radius and diameter.
Curated OER
Measuring the Area of a Circle
When mathematical errors happen, part of the learning is to figure out how it affects the rest of your calculations. The activity has your mathematicians solving for the area of a circular pipe and taking into consideration any errors...
Virginia Department of Education
Circles in the Coordinate Plane
Make the connection between the distance formula and the equation of a circle. The teacher presents a lesson plan on how to use the distance formula to derive the equation of the circle. Pupils transform circles on the coordinate plane...
Curated OER
Volume of a Cylinder
Middle and high schoolers calculate the volume of cylinders. They measure the height, radius and diameter of cylinders. Following given formulas, students calculate the area and volume of the cylinder. They compare cylinders and predict...
Curated OER
Diameter, Radius and Area
Students calculate the diameter, radius and area of a circle. In this geometry instructional activity, students investigate the different ratios of a circle. They calculate the surface are of each circle.