Curated OER
Inscribed Angles
Students analyze inscribed angles and intercepted arcs and explore the relationships between the two. They investigate the properties of angles, arcs, chords, tangents, and secants to solve problems involving circles.
EngageNY
Secant Angle Theorem, Exterior Case
It doesn't matter whether secant lines intersect inside or outside the circle, right? Scholars extend concepts from the previous activity to investigate angles created by secant lines that intersect at a point exterior to the...
EngageNY
The Inscribed Angle Alternate – A Tangent Angle
You know the Inscribed Angle Theorem and you know about tangent lines; now let's consider them together! Learners first explore angle measures when one of the rays of the angle is a tangent to a circle. They then apply their...
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.
Curated OER
Circle Proofs
In this circle proofs worksheet, 10th graders complete 4 different problems that include circle proofs. They respond to each of the questions that deal with circle proofs. Then, students read the given information and use the circle...
Curated OER
Angles and Arcs
Students discuss the sum of central angles and use string to create them on circles. They find the measure and length of both minor and major arcs.
Students give examples of concentric, similar, and congruent circles and congruent arcs.
Curated OER
Circle Packing
Students identify different parts and properties of circles. In this geometry lesson, students identify the radius, diameter, semicircle and inscribed angle of a circle. They identify the tangent lines to a circle.
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
Plain Figures And Measuring Figures
Seventh graders investigate the mathematical concept of a sector. They apply the concept to an example problem and then move into a more complex application. They find the area of the side of a cone. This is done as students calculate...
Curated OER
Building Bridges
Students identify the different types of bridges. Using the internet, they research information on how they are built by completing a scavenger hunt. Locating a specific area, they determine which type of bridge would be appropriate and...
EngageNY
Secant Lines; Secant Lines That Meet Inside a Circle
Young mathematicians identify different cases of intersecting secant lines. They then investigate the case where secant lines meet inside a circle.
Curated OER
DEAD MAN'S CURVE
Ninth graders, after being given a unique scenario and a task sheet on Dead Man's Curve, calculate and explain the force needed to keep a car on a curve using a set of formulas and a geometric property of circles. They utilize and create...
Curated OER
Math: Tangents
Students discover how to recognize tangents and how to use their properties. They investigate and use the properties of angles, arcs, chords, tangents, and secants. Students use two tangents and the properties of similar triangles to...
Curated OER
Worksheet 29 Spring 1999
In this math worksheet, students describe in terms of reflections what happens to a point when (r, θ) in polar coordinates changes. They also discuss the concept of symmetry.
Cuemath
Cuemath: Arc Length
Learn all about arc length. This lesson targets what is arc length and the different formulas used to calculate it. Check-out the interactive simulations to know more about the lesson and try your hand at solving a few interesting...
Texas Instruments
Texas Instruments: Angles Formed by Intersecting Chords, Secants, and Tangents
In this activity, students will investigate properties of angles and arcs formed when chords, secants, and tangents intersect and intercept arcs in a circle. They discover several important theorems concerning circles and arc sizes. They...
CK-12 Foundation
Ck 12: Geometry: Circles: Segments and Lengths Study Guide
This study guide on circles covers some vocabulary and theorems about segments and lengths. It is available for download with free registration.
Math2
Math2: Circles
This site has many useful formulas and examples relating to circles, including related definitions, circumference of a circle, area of a circle, length of a circular arc, area of a circular sector, equation of a circle in cartesian...
Math Open Reference
Math Open Reference: Circles
A complete reference guide to circles including parts, angles, and arcs. It provides definitions and interactive activities that enhance further explanation.
Varsity Tutors
Varsity Tutors: Hotmath: Graphing Calculator Practice Problems: Circles
Practice using your graphing calculator for drawing circles and for finding measurements for circles and parts of the circle. If you get stumped or if you would like to check your work, then select the View Solution button, which is...
Cuemath
Cuemath: Circles
Explore everything about circles. Learn various parts of a circle like a diameter, radius, circumference, circles chord, tangent circles, major arc, segment, sector, and discover other interesting aspects of it. Try your hand at solving...
National Council of Teachers of Mathematics
The Math Forum: Problems Library Geometry Triangles
This site contains a wealth of problems that deal with the basic definitions of medians, altitudes, angle bisectors, and perpendicular bisectors or the defining characteristics of the different types of triangles. There are also...
Alabama Learning Exchange
Alex: Talking in Circles
The students will identify parts of the circle including center, radius, diameter, chord, and arc. This lesson plan was created by exemplary Alabama Math Teachers through the AMSTI project.
CK-12 Foundation
Ck 12: Geometry: Inscribed Angles in Circles
[Free Registration/Login may be required to access all resource tools.] This concept teaches students properties of inscribed angles and how to apply them.