### We found 19,096 reviewed resources for circles

Lesson Planet

#### Lines of Symmetry for Circles

Further your instruction on geometrical symmetry with an investigation of circles. Fourth graders come to realize that the lines of symmetry of a circle are infinite.

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#### Writing the Equation for a Circle

Circles aren't functions, so how is it possible to write the equation for a circle? Pupils first develop the equation of a circle through application of the Pythagorean Theorem. The instructional activity then provides an exercise set...

Lesson Planet

#### 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...

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#### 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...

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#### Circular Motion

You can make sure your physicists' heads are not spinning when studying circular motion by assigning this worksheet as homework. In it, they describe tangential and rotational speed, define centripetal force, explain why centrifugal...

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#### Area of a Circle

A second installment in a series on circles, this production demonstrates the process of finding the area of a circle. As an introductory tool, it is effective. However, it does not explain the reasoning behind the formula because that...

Lesson Planet

#### Circles Centered at the Origin: Dog

How many bones can a dog on a leash reach? Class members move a dog on the end of its leash and determine whether it can reach bones located at specific points. The learners see whether the bone lies on the circle or outside of the...

Lesson Planet

#### 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...

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#### Circle Reasoning

Derive the equation of a circle using the Pythagorean Theorem. Pupils then use the equation to graph circles on a coordinate plane. Their final activity provides information about a circle such as an equation, center, radius, or two...

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#### Discovering the Formulas for Circumference and Area of a Circle

Find formulas using direct measurements and reconstruction. Groups use diagrams of circles and measure their circumferences. With several examples, classmates determine the constant of variation, pi. Pupils continue exploring circle...

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#### How Do You Find the Area of a Sector of a Circle?

How do you find the area of a sector of a circle? Use the formula of course. Then all you have to do is plug in the given values and do the math. Make sure you are following the rules of order of operation. The instructor will walk you...

Lesson Planet

#### Graphing Circles: Lesson

Explore a standard method to graph a circle. Given the standard form of the equation of a circle, the segment of a basic geometry playlist shows how to graph the circle. The resource works examples of graphing a circle, finding the...

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#### Trigonometric Functions: The Unit Circle

This comprehensive problem and note set walks the class through a large part of simplifying trigonometric expressions using the unit circle and identities. From identifying angles to applying appropriate trigonometric ratios, problems...

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#### How to Remember the Unit Circle

Seeing structure in the patterns is key to understanding the unit circle, and it takes time to become comfortable with those relationships. The video gives learners access to repeated instruction to allow time to develop those patterns.

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#### Circles, What Is Pi?

Understanding the basic of circles is as easy as pi. The resource introduces the definition of a circle along with its dimensions, circumference, diameter, and radius. Using graphics, the video shows the approximation of pi and how to...

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#### Angles On and Inside a Circle: Lesson

A video introduces methods to find the measure of angles whose vertex is on and inside a circle. Within examples, the section of a larger playlist on basic geometry incorporates several angle measurement theorems.

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#### Measures of Circular Motion

Physicists become Olympians in a competition using centripetal force. They ride a bicycle to comprehend relationships between linear and rotational motion. If you have an old-fashioned record player, it can be used to help pupils...

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#### 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...

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#### Explaining the equation for a circle

By first starting with an explicit example of a radius and center point, this challenging lesson tries to help high schoolers gain an understanding of the Pythagorean theorem and the equation of a circle. Once they have accomplished the...

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#### Best Circle

Drawing the perfect circle is harder than one would think! What makes a circle a circle and how can you define that with a formula? Young mathematicians devise their own methods of analyzing the imperfections of circle drawings. Using...

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#### Drawing a Line Tangent to a Circle

Explore lines tangent to a circle. In this math lesson, young scholars 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 works...

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#### Penny Circle

Watch as your classes buy into a rich lesson full of information. A video opener challenges individuals to determine the number of pennies that fit in a circle with a 22-inch diameter. Using lesson materials, scholars collect data and...

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#### Episode 6: Circular Flow

Does it ever seem like the more money you get, the more you spend? A short video lesson introduces the concept of goods and services changing hands in a circular flow pattern. Scholars analyze how businesses make money from selling goods...

Lesson Planet

#### Coins in a Circle

Round and round you'll go! Learners watch as different-sized circles fill with coins. They collect data and then make a prediction about the number of coins that will fit in a large circular rug.