Worksheet
Mt. San Antonio Collage

Circles

For Students 9th - 12th Standards
Don't circle around the topic, but get right to the center with tons of practice regarding circles in geometry. The note-incorporated learning exercise provides guided practice through many topics such as central angles, inscribed...
Unit Plan
Mathematics Vision Project

Circles: A Geometric Perspective

For Teachers 10th - 12th Standards
Circles are the foundation of many geometric concepts and extensions - a point that is thoroughly driven home in this extensive unit. Fundamental properties of circles are investigated (including sector area, angle measure, and...
Assessment
Inside Mathematics

Circles in Triangles

For Teachers 9th - 12th Standards
Challenge the class with inscribed circles in triangles. The assessment task requests class members use their knowledge of circles and right triangles to prove two triangles are congruent. They go on to utilize their knowledge of...
Interactive
CK-12 Foundation

Length of a Chord: Distance Across a Ferris Wheel

For Students 9th - 12th Standards
An interactive presents two friends on a ferris wheel with the task of finding the distance between the them. Pupils create the chord between the two friends and calculate its lengths using trigonometric ratios.
Assessment
EngageNY

Geometry Module 5: Mid-Module Assessment

For Teachers 9th - 12th Standards
How can you formally assess understanding of circle concepts? Pupils take a mid-module assessment containing five questions, each with multiple parts.
Lesson Plan
West Contra Costa Unified School District

Arcs and Angles

For Teachers 9th - 12th
Noah didn't construct this kind of arc. High school scholars first explore how angles can be formed in circles. They then learn relationships between angles and arcs by conducting an exploratory activity where they position and draw arcs...
Lesson Plan
EngageNY

Secant Lines; Secant Lines That Meet Inside a Circle

For Teachers 9th - 12th Standards
Young mathematicians identify different cases of intersecting secant lines. They then investigate the case where secant lines meet inside a circle.
Lesson Plan
Virginia Department of Education

Arc Length and Area of a Sector

For Teachers 9th - 11th Standards
What do skateboarding and baked goods have in common with math? You can use them to connect half-pipe ramps and cakes to arcs and sectors. Pupils compare the lengths of three different ramp options of a skate park. They calculate the...
Lesson Plan
EngageNY

Secant Angle Theorem, Exterior Case

For Teachers 9th - 12th Standards
It doesn't matter whether secant lines intersect inside or outside the circle, right? Scholars extend concepts from the previous lesson to investigate angles created by secant lines that intersect at a point exterior to the circle....
Lesson Plan
EngageNY

The Inscribed Angle Alternate – A Tangent Angle

For Teachers 9th - 12th Standards
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...
eBook
CK-12 Foundation

Ck 12: Interactive Geometry: 8.3 Central Angles and Chords

For Students 9th - 10th Standards
Learn and understand central angles and chords.
Unit Plan
CK-12 Foundation

Ck 12: Geometry: Segments From Chords

For Students 9th - 10th Standards
[Free Registration/Login may be required to access all resource tools.] Looks at how to apply the Intersecting Chords Theorem.
Unit Plan
Oswego City School District

Regents Exam Prep Center: Circles, Segments, and Area

For Students 9th - 10th Standards
A wealth of resources to supplement instruction on parts of the circle. Find lessons describing chords, tangents, secants, and segments, as well as related practice quizzes and classroom activities.
Unit Plan
CK-12 Foundation

Ck 12: Geometry: Chords in Circles

For Students 9th - 10th Standards
[Free Registration/Login may be required to access all resource tools.] In this lesson, students apply chord theorems. Students examine guided notes, review guided practice, watch instructional videos and attempt practice problems.
Activity
CK-12 Foundation

Ck 12: Parts of Circles

For Students 9th - 10th Standards
[Free Registration/Login Required] Students will explore how the length of a chord in a circle changes by moving the points of the chord. Click learn more to watch a video and click challenge me to answer a practice question.
Activity
CK-12 Foundation

Ck 12: Area of Sectors and Segments: Pacman Area

For Students 9th - 10th
[Free Registration/Login Required] Students are to determine the area of the shaded region between two radii. Click challenge me to answer practice questions and click learn more to watch a video.
Unit Plan
CK-12 Foundation

Ck 12: Geometry: Chords in Circles

For Students 9th - 10th Standards
[Free Registration/Login may be required to access all resource tools.] This concept teaches students four theorems about chords and how to apply them. Students examine guided notes, review guided practice, watch instructional videos and...