Virginia Department of Education
Going the Distance
Estimate the value of one of the most famous irrational numbers. The hands-on lesson instructs classmates to measure the circumference and diameters of circles using yarn. The ratio of these quantities defines pi.
Mathed Up!
Area and Circumference of Circles
Don't go around and around, help your class determine amounts around and in a circle with a video that connects circumference to the perimeter or the distance around an object. The resource includes 14 questions dealing with circles and...
Curated OER
Radius, Diameter and Area
Students identify the radius and diameter of a circle. In this geometry instructional activity, students calculate the volume and area of a cylinder and circle. They relate the circumference of a circle to Pi.
EngageNY
Rectangles Inscribed in Circles
Putting a rectangular object into a circular one—didn't the astronauts on Apollo 13 have to do something like this? Learners first construct the center of a circle using perpendiculars. They then discover how to inscribe a rectangle in a...
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
Circle Area, Perimeter and Circumference
Use this geometry skills practice activity to have learners solve seven problems that require them calculate the circle area, perimeter, and circumference of circles.
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...
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...
CK-12 Foundation
Equations of Circles: The Sea of Happiness
Map this! Help your young mathematicians draw a circular island on a map. Given specifics of the location and size of an island on a map, pupils transform a circle to meet the given requirements. They then determine the location of the...
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
Circles
In this circles worksheet, 10th graders solve and complete 13 various types of problems. First, they solve each set of triangles for the given variable. Then, students name a radius, a diameter, a tangent, a secant, a point of tangency,...
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
Circle Formulas
Tenth graders apply various circle formulas to determine radii, diameter, circumference, area, arc length, and sector area. The two page learning exercise contains twenty-five problems. Answers are not provided.
Curated OER
Circumference and Area of Circles
In this circles instructional activity, students use given radius or diameter measurements and find the circumference and area of circles to one decimal place.
Inside Mathematics
Circles in Triangles
Challenge the class with inscribed circles in triangles. The assessment task requests class members use their knowledge of circles and right triangles to prove two triangles are congruent. They go on to utilize their knowledge of...
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...
Mrs. Burke's Math Page
Let Them Eat Pi
Looking for a fun and creative way to celebrate Pi Day? Then this is the resource for you. From a scavenger hunt and trivia contest to PowerPoint presentations and skills practice worksheets, this collection of materials is a...
Curated OER
Find Radius/Diameter
In this geometry worksheet, students calculate the radius and the diameter of the five given circles. There is an answer key included.
Curated OER
Basic Circle Worksheet
In this circle worksheet, students identify center, radius and diameter of three circles. An answer key is included on page 2.
Curated OER
Area Of A Circle
Learners investigate the concept of area and how it can be applied to a circle. They use the right formula in order to solve different problems. The teacher leads the class through different examples and serves as a resource during...
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.
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 instructional activity includes links to both PowerPoints as well as a worksheet...
Curated OER
Don't Be a Square
Students analyze the relationship between radius and diameter. Students read Sir Cumference and the First Round Table then take measurements of circular items from around the room. Students compute the radius, diameter...
Curated OER
Find Radius of the Circles
In this finding the radius of circles instructional activity, learners must calculate the radius of 4 circles. Students are given diameter and must write the radius on the line for each circle.