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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 worksheet provides guided practice through many topics such as central angles, inscribed polygons and...
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Assessment
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CCSS Math Activities

Smarter Balanced Sample Items: High School Math – Claim 3

For Teachers 9th - 12th Standards
Communication is the key. A presentation provides 25 sample items for Claim 3, Communicating Reasoning, for the Smarter Balanced High School Math assessment. Items require pupils to answer the question and provide logical reasoning to...
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Unit Plan
Mathematics Vision Project

Module 5: Circles A Geometric Perspective

For Teachers 9th - 12th Standards
Circles, circles, everywhere! Pupils learn all about circles, central angles, inscribed angles, circle theorems, arc length, area of sectors, and radian measure using a set of 12 lessons. They then discover volume formulas through...
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Lesson Plan
Mathematics Assessment Project

Solving Problems with Circles and Triangles

For Teachers 9th - 12th Standards
After completing a task involving examining the ratio of areas of triangles and circles in a given figure, scholars examine sample responses to identify other strategies they could use to solve the problem.
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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.
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Lesson Plan
EngageNY

The Angle Measure of an Arc

For Teachers 9th - 10th Standards
How do you find the measure of an arc? Learners first review relationships between central and inscribed angles. They then investigate the relationship between these angles and their intercepted arcs to extend the Inscribed Angle Theorem...
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Assessment
Georgia Department of Education

Analytic Geometry Study Guide

For Students 9th - 12th Standards
Are you looking for a comprehensive review that addresses the Common Core standards for geometry? This is it! Instruction and practice problems built specifically for standards are included. The material includes geometry topics from...
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Lesson Plan
Illustrative Mathematics

Two Wheels and a Belt

For Teachers 9th - 10th Standards
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...
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Activity
Illustrative Mathematics

Similar Circles

For Teachers 9th - 10th Standards
Young geometers flex their transformation muscles in this brief but powerful exercise using dilations and translations to develop the similarity of circles. The plan provides guidelines to help learners navigate a pair of deceptively...
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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...
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Website
National Council of Teachers of Mathematics

The Math Forum: Ask Dr. Math: Faq About Proofs

For Students 9th - 10th Standards
This site provides links to questions sent in to Dr. Math about proofs. Topics covered include what proofs are, how to understand them, and how to build them, and much more. Be sure to click on the links which you believe may be helpful.
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Activity
Maths Challenge

Maths challenge.net: Perpendicular Construction

For Students 9th - 10th Standards
This is a "three star" geometry problem where prior math problem skills and proof experience is recommended to solve this "Perpendicular Construction" problem.
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Activity
Maths Challenge

Maths challenge.net: Tick Tock Triangle

For Students 9th - 10th Standards
This is a "three star" geometry problem where prior knowledge of probability is required to solve this "Tick Tock Triangle" problem, have fun!
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Activity
Maths Challenge

Maths challenge.net: Leaning Ladders

For Students 9th - 10th Standards
Use your right triangle solving skills to solve this ladders in a hole problem.
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Activity
Maths Challenge

Maths challenge.net: Right Triangle Equal Parts

For Students 9th - 10th Standards
A geometry proof problem involving a right triangle and finding angles of equal measure.
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Activity
Maths Challenge

Maths challenge.net: Bag of Balls

For Students 9th - 10th Standards
A "three star" geometry problem which requires prior math problem solving skills and proof writing skills to solve this "Bag of Balls" radius of balls problem.
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Activity
Maths Challenge

Maths challenge.net: Equal Angles

For Students 9th - 10th Standards
A geometric proof. Prove two angles in this model are equal in measure.
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Activity
Maths Challenge

Maths challenge.net: Triangle in a Square

For Students 9th - 10th Standards
A "three star" geometry problem requiring some prior knowledge in math and proofs to maximize the area of an inscribed triangle in terms of the hypotenuse.
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Activity
Maths Challenge

Maths challenge.net: Inscribed Rectangle

For Students 9th - 10th Standards
This is a proof problem, considered a "three star" geometry problem requiring knowledge of proofs and properties of circles to solve this equal area of inscribed polygons problem.
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Handout
Maths Challenge

Maths challenge.net: Three Circles

For Students 9th - 10th Standards
This is a proof problem, considered a "three star" geometry problem requiring knowledge of proofs and properties of circles.
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Activity
Maths Challenge

Maths challenge.net: Measuring Mountains

For Students 9th - 10th Standards
Use your triangle solving skills to solve this triangle problem and then apply it to the real world.
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Activity
Maths Challenge

Maths challenge.net: Annulus

For Students 9th - 10th Standards
An annulus of a circle is defined and then a proof like problem is posed involving area and radius of circles.
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Activity
Maths Challenge

Maths challenge.net: Maximum Square

For Students 9th - 10th Standards
A challenging proof like geometry of finding the square inscribed in a triangle.
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Activity
Maths Challenge

Maths challenge.net: Isosceles Trapezium

For Students 9th - 10th Standards
This is a "three star" geometry problem where prior knowledge of problem solving and thinking through proofs is recommended to solve this trapezoid inscribed in a semicircle problem.