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 instructional activity, pupils understand how to find the radius,...
Mathed Up!
Area of Sector and Length of Arcs
Viewers learn how to apply proportional reasoning to find area of sectors and arc lengths with a video that starts off explaining how to find the areas of circle sectors and the lengths of arcs. Scholars then practice solving problems...
Curated OER
Areas of Geometric Shapes with the Same Perimeter
A triangle, square, hexagon, and circle all have a perimeter of one unit. Eighth graders must attempt to find the area of each and arrange them in order from least to greatest areas. A terrific task for applying four different...
Curated OER
Finding the Area of Polygons
Third graders are exposed to finding the area of polygons by decomposing figures and recomposing them into rectangles. This strategy allows children to expand on their prior knowledge of constructing shapes by rearranging parts into...
Curated OER
Area of Circles and Probability
Learners investigate the area of squares and circles. In this geometry lesson plan, students calculate the area and probability of simple events. They work on a laptop using Safari.
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...
Curated OER
The Circumference of a Circle and the Area of the Region it Encloses
Bring your math class around with this task. Learners simply identify parts of a given circle, compute its radius, and estimate the circumference and area. It is a strong scaffolding exercise in preparation for applying the formulas for...
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...
EngageNY
Proving the Area of a Disk
Using a similar process from the first lesson in the series of finding area approximations, a measurement resource develops the proof of the area of a circle. The problem set contains a derivation of the proof of the circumference...
Illustrative Mathematics
Eight Circles
We are used to finding the area of a circle by plugging the radius into an equation. Here, learners are required to go further to find multiple areas and calculate the difference. They must detect a pattern in order to figure out the...
EngageNY
Real-World Area Problems
Not all structures take the shape of a polygon. The 21st lesson in a series of 29 shows young mathematicians they can create polygons out of composite shapes. Once they deconstruct the structures, they find the area of the composite figure.
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...
EngageNY
More Problems on Area and Circumference
Perimeter check! Pairs work on finding the areas of semicircles and quarter circles using a relationship with squares. The problems challenge pupils to find areas of composite figures made from rectangles, semicircles, and quarter circles.
Curated OER
Quiz: Area of a Circle
Geometers test their mastery at finding the area of a circle with 10 basic problems. Circle diagrams show line segments, points, and diameter. Distance of radii are given. They use pi as 3.14 to calculate the area. No answer key is...
EngageNY
Unknown Length and Area Problems
What is an annulus? Pupils first learn about how to create an annulus, then consider how to find the area of such shapes. They then complete a problem set on arc length and areas of sectors.
CK-12 Foundation
Volume by Disks: The Vase Case
Finding the volume is an integral characteristic of a vase. Using the idea that summing the areas of cross-sectional disks will calculate the volume of a rotational solid, pupils find the volume of a vase. Scholars determine the interval...
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
Area of a Circle When Radius is Given
Five problems provide practice for learners to find the area of a circle given the distance of the radius. Answers on the key use pi as a variable and do not include fully computed numeric answers. To reinforce basic multiplication facts...
Flipped Math
Unit 9 Review: Area of Polygons
It's time to show what you know! Individuals first review finding the area of polygons using the formulas from parallelograms to regular polygons. They then brush up on finding the area and circumference of circles, as well as reviewing...
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
Calculate Area Using Pi
Geometers find the area of four circles given their circumferences. Circumference is presented in the form of "numeral (diameter) x pi"; the answer key shows solutions as "numeral (radius squared) x pi," so computation is...
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...
Curated OER
Area of Circle Worksheet
Given the diameter of a circle, learners are charged with finding its area. They halve the diameter, square it, and multiply by pi. Five problems provide basic practice.
EngageNY
What Is Area?
What if I can no longer justify area by counting squares? Lead a class discussion to find the area of a rectangular region with irrational side lengths. The class continues on with the idea of lower approximations and...