EngageNY
Geometry Module 5: End-of-Module Assessment
The lessons are complete. Learners take an end-of-module assessment in the last installment of a 23-part module. Questions contain multiple parts, each assessing different aspects of the module.
EngageNY
Properties of Tangents
You know about the tangent function, but what are tangent lines to a circle? Learners investigate properties of tangents through constructions. They determine that tangents are perpendicular to the radius at the point of tangency,...
CK-12 Foundation
Restricted Domain and Range: Restricted Circle Radius and Area
There's no restriction to how much your class can learn about domain and range. Users of an interactive adjust the radius of a circle to see its effects on the area. They note how restrictions in the domain (radius) relate to...
EngageNY
The Most Famous Ratio of All
Pupils develop a definition of a circle based upon its radius in the 17th segment of a 28-part series. They determine the relationship between the radius and the diameter of a circle. To round out the lesson, they use the formula for the...
Balanced Assessment
Oops! Glass Top
A short assessment asks participants to find the original radius required to replace a table top. The problem provides a hypothetical situation of having a segment of a broken glass table top. Pupils find the radius of the...
101 Questions
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.
Virginia Department of Education
Surface Area and Volume of a Cylinder
Surface area or volume? Pupils first review the difference between surface area and volume. They then use a two-dimensional net that helps them develop formulas for the surface area and volume of cylinders.
Curated OER
Parts of a Circle
Sixth graders use yarn, paper plate, and other materials to identify parts of a circle. In this parts of a circle lesson plan, 6th graders identify the circumference, radius, diameter, and other parts of a circle.
Curated OER
Circumference and Area of Circles (B)
In this geometry activity, 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
Parts of a Circle
For this geometric shapes worksheet, students respond to questions that require them to identify chords, radii, diameters and centers of 4 circles.
Curated OER
Exploring Circles
Students explore circles using a graphing calculator. For this circles lesson, students write the equation of a circle with a given center and radius length. Students find the most appropriate model for each combination of data they...
Concord Consortium
Circumscribed Polygon
Trigonometry teachers often go off on a tangent, and here's a instructional activity that proves it! First, young mathematicians use a formula with tangent to prove a formula correct for area. Then, they draw conclusions about the area...
Curated OER
Pi Day: The Other Math Holiday!
Happy Pi Day! This collection of games, experiments, and activities leads participants through an exploration of the many aspects and attributes of that mysterious quantity, pi. Activities range from using statistical...
Curated OER
Algebra II - Lesson 10-3: Circles
In this equations of circles worksheet, learners solve 4 short answer problems. Students find an equation of a circle given the center and radius.
Curated OER
Write the Parts of the Circle in the Place Holders
In this parts of a circle activity, students place the names of 6 different parts of a circle in rectangular place holders. They use labels such as cord, secant, diameter, radius, tangent, and center.
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.
Concord Consortium
Outward Bound
Just how far can I see? The short assessment question uses the Pythagorean Theorem to find the distance to the horizon from a given altitude. Scholars use the relationship of a tangent segment and the radius of a circle to find the...
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...
101 Questions
Apple Mothership
Explore Apple's spaceship office building. Built in the shape of a circle, the office building offers a unique floor plan challenge. Young scholars use the dimensions of the building to estimate the square footage for each employee.
Mt. San Antonio Collage
Circles
Don't circle around the topic, but get right to the center with tons of practice regarding circles in geometry. The note-incorporated activity provides guided practice through many topics such as central angles, inscribed polygons...
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.
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. In this geometry lesson, 7th graders work in groups to find the diameter, radius, and circumference of circles....
Curated OER
Circles and Cylinders
In this geometry lesson, 10th graders break down a circle and identify the different parts. They discuss chords, diameter, radius, circumference, major and minor segment. There are 42 problems broken down into 5 different sections.
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.