EngageNY
Equations for Tangent Lines to Circles
Don't go off on a tangent while writing equations of tangent lines! Scholars determine the equations for tangent lines to circles. They attempt both concrete and abstract examples, such as a tangent line to the unit circle through...
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...
EngageNY
Construct a Square and a Nine-Point Circle
Anyone can draw a square, but can you CONSTRUCT a square? Here is a resource that challenges math scholars to create steps to finish their own construction. They test their ability to read and follow directions to complete a construction...
EngageNY
Geometry Module 5: Mid-Module Assessment
How can you formally assess understanding of circle concepts? Pupils take a mid-module assessment containing five questions, each with multiple parts.
Curated OER
Geometry: Area, Scale Factor, Circumference
In this geometry worksheet, students solve 10 problems regarding area, scale factors, and circumference. Students, in 3 of the problems, are given the circumference and asked to work backwards to find missing information.
Curated OER
Finding Circumference and Area of a Circle
Young geometers explore the concept of circumference and area of circles. They discuss what information is needed to find circumference and area. The resource employs several instructional methods: Frayer Model for Vocabulary, literature...
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.
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,...
Curated OER
Tangent Lines and the Radius of a Circle
Your Geometry learners will collaboratively prove that the tangent line of a circle is perpendicular to the radius of the circle. A deliberately sparse introduction allows for a variety of approaches to find a solution.
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...
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...
Mathematics Assessment Project
Temple Geometry
Temper your excitement of temple geometry. Using algebraic and geometry concepts to determine various measurements in a circle diagram, scholars determine the shaded area of the diagram.
Virginia Department of Education
Angles, Arcs, and Segments in Circles
Investigate relationships between angles, arcs, and segments in circles. Pupils use geometry software to discover the relationships between angles, arcs, and segments associated with circles. Class members use similar triangles to...
Mathematics Vision Project
Module 6: Connecting Algebra and Geometry
A geometry module connects algebraic reasoning to geometry. It challenges scholars to investigate the slope criteria for parallel and perpendicular lines, prove theorems involving coordinate geometry, and write equations for circles and...
Mathematics Assessment Project
Geometry
Help learners find joy in facing mathematical challenges. The questions posed on this worksheet encourage young mathematicians to utilize skills learned throughout a geometry unit, and to apply themselves and persevere through...
Curated OER
Circumscribing a Circle About a Triangle
Pupils circumscribe a circle about a triangle. They construct a triangle using Cabri Jr and then circumscribe it. They then use knowledge of perpendicular bisectors and circumcenters to locate the center of the circle and then...
Texas Instruments
Area of Circles
High schoolers 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
Geometry Review
In this geometry review worksheet, 10th graders solve and complete 33 different problems that include identifying various geometric figures and parts of a circle. First, they find the radius of each circle given its diameter. Then,...
Curated OER
Chords of a Circle
In this geometry worksheet, 10th graders calculate the length of a chord and the distance from the center of a circle or radius. They compare diameter, chords and radius. There are 10 questions with an answer key.
Curated OER
Skills Practice: Area of Circles
Two practice pages with 10 problems each show circles and give their radii. Learners calculate the area. Answers are provided.
Curated OER
Discovering Pi/Welcome to Pi Day
Students explore pi. In this circle measurement lesson, students define and identify radius, diameter, circumference, and perimeter. Students work in groups to measure several plastic lids and record their findings. Students compare the...
Curated OER
Angles, Triangles, Quadrilaterals, Circles and Related
Students classify angles. For this angles lesson, students explore the characteristics of angles, triangles, quadrilaterals and circles. They identify polygons and sing a classifying angles song. Students participate in a manipulative...
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.
Illustrative Mathematics
Two Wheels and a Belt
Geometry gets an engineering treatment in an exercise involving a belt wrapped around two wheels of different dimensions. Along with the wheels, this belt problem connects concepts of right triangles, tangent lines, arc length, and...