Curated OER
Circle Proofs
In this circle proofs learning exercise, 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...
Maths Challenge
Maths challenge.net: Circular Pipes
A realistic world problem using the knowledge of chords and the parts of a circle to solve. Test your knowledge on this brain teaser!
Government of Alberta
Learn Alberta: Math Interactives: Exploring Circle Geometry Properties
Investigate circles, namely their angles, chords, and tangents using this highly interactive Learn Alberta math. Explore a number of circle geometry properties that can be used to determine unknowns. Be sure to follow the link to the...
Music Theory
Music theory.net: Chord Ear Trainer
This online quiz gives students a chance to recognize triads and seventh chords, by listening to audio clips. Teachers can customize this quiz and print out progress reports.
Music Theory
Music theory.com: Introduction to Chords
A description of augmented and diminished triads/ chords. Provides illustrated examples with highlighted vocabulary words,a printable chart, and audio clips to supplement the lesson.
Varsity Tutors
Varsity Tutors: Hotmath: Practice Problems: Circle Exercises
Twenty-five problems cover various circle activities. They are given with each step to the solution cleverly revealed one at a time. You can work each step of the problem then click the "View Solution" button to check each step of your...
Cuemath
Cuemath: Segment of a Circle
This lesson expands your knowledge about circles by learning about the segment of a circle, which will include its mathematical definition, area of the segment, types of segments in a circle, theorems based on a segment of a circle, and...
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...
Cuemath
Cuemath: Chords of a Circle
A comprehensive guide for learning all about chords of a circle with definitions, chords of a circle theorems, intersecting chords theorem, congruent circles, diameter, solved examples, and practice questions.
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...
Wolfram Research
Wolfram Math World: Chord
Describes what a chord is and shows a diagram and shows how to find areas using integral calculus.
Texas Instruments
Texas Instruments: Chords, Secants, and Tangents
Students construct chords, secants, and tangents. From those constructions, they develop a deeper understanding of the terms, as well as explore certain properties of the constructions.
Texas Instruments
Texas Instruments: Cabri Jr. Perpendicular Bisector of a Circle
This activity uses Cabri Jr. to discover that the perpendicular of a chord passes through the centre of a circle. Microsoft Word documents are attached to support the lesson.
Texas Instruments
Texas Instruments: Perpendicular Segments in a Circle
Students learn about chords of a circle. They draw a line perpendicular to the chord and passing through the center of the circle. They explore the lengths of the two segments of the chord. They investigate with a different chord and...
Texas Instruments
Texas Instruments: Cabri Jr. Tangent to a Chord
This activity uses Cabri Jr. to discover that the angle between a tangent and a chord is equal to the inscribed angle on the opposite side of the chord.
Mr. Martini's Classroom
Mr. Martini's Classroom: Circles Geometry Review
This resource provides two levels of multiple choice questions to review the parts of a circle as well as area and perimeter.
Other
Better Guitar: Chord Basics
An excellent tutorial for learning chords for the guitar. Tells what chords are, chord names, what chord blocks and barre chords are, and how to move chord shapes up the guitar neck to create new chords. Gives examples and pictures that...
CK-12 Foundation
Ck 12: Trigonometry: Length of a Chord
[Free Registration/Login may be required to access all resource tools.] Find the length of a chord of a circle.
CK-12 Foundation
Ck 12: Geometry: Circumference
[Free Registration/Login may be required to access all resource tools.] In this lesson students calculate a circle's circumference. Students examine guided notes, review guided practice, watch instructional videos and attempt practice...
CK-12 Foundation
Ck 12: Geometry: Parts of Circles
[Free Registration/Login may be required to access all resource tools.] Name the parts of a circle.
OpenStax
Open Stax: Catherine Schmidt Jones: Naming Triads
Learn about the various types of triads. This lesson focuses on the chords in root position. Included in this site are a few self checking tests.
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.
CK-12 Foundation
Ck 12: Geometry: Parts of Circles
[Free Registration/Login may be required to access all resource tools.] This concept teaches students the vocabulary for the parts of circles, including lines passing through circles.
CK-12 Foundation
Ck 12: Geometry: Segments From Chords
[Free Registration/Login may be required to access all resource tools.] This concept teaches students to apply the Intersecting Chords Theorem to solve for missing segments from chords.