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...
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...
West Contra Costa Unified School District
Finding the Equation of a Circle
Tired of going around and around for a resource on circles? Scholars determine the general equation of a circle on a coordinate plane, then participate in an activity matching equations to the radii and centers of the circles...
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
Circumference and Area of Circles (A)
In this geometry activity, students solve 12 problems in which the area and circumference of a circle is calculated to the tenth place. No formulas are given on this page.
Curated OER
Area of a Circle Worksheet
In this geometry worksheet, 6th graders identify the area of the four given circles by using the given diameters. There is a space for students to show their work.
Curated OER
Circumference and Area of Circles (B)
In this geometry worksheet, students calculate the area and circumference of 12 circles in which either the diameter or radius is shown. There are no formulas given on this page.
Curated OER
Geometry: Calculating the Area of a Circle
In this area worksheet, students use the perimeter or radius to determine the area of a circle. This one-page worksheet contains 8 problems. This worksheet may be produced in printed form. Answers may be viewed on-line.
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.
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...
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...
Illustrative Mathematics
Hexagonal Pattern of Beehives
Young geometers and biologists investigate the math of nature in an activity that is just the bee's knees. Participants will study the tessellations of hexagons in a beehive, along with the natural rationale behind the specific shape....
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.
EngageNY
Area Problems with Circular Regions
Uncover strategies for finding areas of composite figures. The 23rd lesson in a 29-part module has young mathematicians decompose figures to find total area. Figures decompose to rectangles and circular regions.
Curated OER
Area of a Circle
In this geometry learning exercise, 10th graders are asked to calculate the area of a circle given the radius of the circle. There is an answer key for these 9 problems.
Virginia Department of Education 
Exploring 3-D Geometry
Take young mathematicians on an exploration of the world of 3-D geometry with this seven-lesson unit. After first defining the terms perimeter, area, and volume and how they apply to the real world, students continue on...
Curated OER
Chords of a Circle
Teach how to differentiate between chords and perpendicular bisectors. In this geometry lesson, students relate the properties of chords and circle to solving right triangle. They define what makes two chords congruent in side a circle.
Curated OER
Coordinate Grid: Area and Circumference of Circles
Here is a geometry worksheet in which learners plot the points of a circle onto a coordinate grid and proceed to calculate the area or circumference of the circle. There are four questions.
Texas Instruments
Drawing a Line Tangent to a Circle
Explore lines tangent to a circle. In this math lesson plan, students manipulate circles and lines on a TI calculator. They draw a circle  and analyze perpendicular lines intersecting the circle in only one place. This activity...
Curated OER
Inscribing a Square in a Circle
Inscribing a square in a circle brings up a number of interesting geometry topics including triangle congruence and how to prove a quadrilateral is a square. This activity is followed up by finding the area of the square and determining...
Teach Engineering
Discovering Relationships Between Side Length and Area
Consider the relationship between side length and area as an input-output function. Scholars create input-output tables for the area of squares to determine an equation in the first installment of a three-part unit. Ditto for the area of...
Illustrative Mathematics
Stained Glass
A complex question looking for the total cost of a stained glass window by calculating area and circumference of a circle. With detailed components, this activity will challenge your designers to figure out if they have enough money to...
Curated OER
Equation of a Circle
Learners write the equation of a circle. In this geometry lesson, students check the solution of a coordinate pair by evaluating them. They graph the circle given the equation and radius.
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.
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
