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 Software for Constructions

For Students 9th - 10th Standards
[Free Registration/Login Required] Students explore the concept of using geometry software to construct geometric shapes by navigating through the interactive learning module and then answering questions that go along with the module....
Handout
National Council of Teachers of Mathematics

The Math Forum: Ask Dr. Math: "Impossible" Geometric Constructions

For Students 9th - 10th
Three geometric constructions students like to say are "impossible" are explained here. Trisecting an angle, squaring a circle, and doubling a cube are examined as being either possible or impossible, depending on the "rules" you use.
Activity
Math Open Reference

Math Open Reference: Constructions

For Students 9th - 10th Standards
Learn about drawing shapes using only a compass and straight edge or ruler with out measuring any lengths or angles.
Activity
Texas Instruments

Texas Instruments: Constructing the Diameter of a Circle

For Teachers 9th - 10th
Given a circle, students will construct a diameter of the circle. They will use the following theorem: In the same circle, if one chord is a perpendicular bisector of another chord, then the first chord is a diameter.
Activity
Texas Instruments

Texas Instruments: Constructing Circles

For Teachers 9th - 10th
In this activity, students will investigate the construction of circles that pass through a given number of points. They will also investigate the number of points needed to generate a unique circle in a plane.
Lesson Plan
Illustrative Mathematics

Illustrative Mathematics: G Co Inscribing a Square in a Circle

For Teachers 9th - 10th Standards
In this lesson plan, students learn how to inscribe a square in a circle. Aligns with G-CO.D.13
Handout
Wolfram Research

Wolfram Math World: Math World: Geometric Construction

For Students 9th - 10th Standards
Offers an explanation of what a geometric construction is and what some of the tools are that are used for it, including the traditional straightedge and compass. The site explains how to construct various polygons inscribed within a...
Primary
Other

Hoover Online!: Circular No. 4

For Students 9th - 10th
A detailed description of three major attempts made by Herbert Hoover and his administration to get money back into circulation and stem the tide of the Great Depression. Read about the Reconstruction Finance Corporation and the...
Website
Other

Antonio Gutierrez: Geometry From the Land of the Incas

For Students 9th - 10th
Discovering the properties of constructions, seeing proofs in action, and viewing problems come to life here with this wonderful use of technology in the classroom. Single steps are explained and illustrated one at a time so that the...
Lesson Plan
Illustrative Mathematics

Illustrative Mathematics: G Co Inscribing an Equilateral Triangle in a Circle

For Teachers 9th - 10th Standards
Suppose we are given a circle of radius r. The goal of this task is to construct an equilateral triangle whose three vertices lie on the circle. Aligns with G-CO.D.13.
Lesson Plan
Illustrative Mathematics

Illustrative Mathematics: g.c Inscribing a Circle in a Triangle Ii

For Teachers 9th - 10th Standards
This task focuses on a fact which comes out of the construction of the inscribed circle in a triangle: the angle bisectors of the three angles of triangle ABC all meet in a point. Aligns with G-C.A.3.
Lesson Plan
Illustrative Mathematics

Illustrative Mathematics: G Co Inscribing a Hexagon in a Circle

For Teachers 9th - 10th Standards
In this task, learners inscribe a regular hexagon inside a circle and compare its area to that of the circle. Aligns with G-CO.D.13.
Lesson Plan
Illustrative Mathematics

Illustrative Mathematics: G C Tangent to a Circle From a Point

For Teachers 9th - 10th Standards
This task builds on a previous one called ''Right triangles inscribed in circles I.'' Here students are asked to construct a tangent line to a circle from a point outside of the circle. Aligns with G-C.A.4.
Activity
Texas Instruments

Texas Instruments: Going in Circles Inscribed Angles

For Teachers 9th - 10th Standards
This lesson has students discover properties of inscribed angles in a circle. Students use the Geometer's Sketchpad application for the TI-89 to construct a circle and an inscribed angle.
Interactive
Physics Aviary

Physics Aviary: Circular Force Lab

For Students 9th - 10th
This lab is designed to have students find the relationships that affect the force required to keep an object moving in a circle. Students will be able to modify the mass of the object, the speed of the object and the size of the circle...
Website
Cut the Knot

Cut the Knot!: Interactive Mathematics: Geometry Articles, Theorems, Problems

For Students 9th - 10th
Contains over five hundred Geometry articles, problems, puzzles, and games. Some sites relating to circles are provided within this list.
Handout
Math Words

Mathwords: Inscribed Circles

For Students 9th - 10th Standards
Mathwords provides an explanation and a diagram of an inscribed circle. By clicking on any of the highlighted words, you will learn about related terms.
Handout
Math Open Reference

Math Open Reference: Square Inscribed in a Circle

For Students 9th - 10th Standards
Learn about a square inscribed in a circle with this handy reference guide. Provides a detailed definition and an interactive activity that enhances further explanation. Includes links to related topics.
Lesson Plan
Texas Instruments

Texas Instruments: Chords, Secants, and Tangents

For Teachers 9th - 10th Standards
Learners 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.
Handout
Depaul University

Depaul University: Inscribing Regular Polygons

For Students 9th - 10th Standards
In this lesson, students learn to inscribe regular polygons inside a circle.
Primary
University at Buffalo

Univ. At Buffalo: Circle Association's Rita Dove Page

For Students 9th - 10th
Site from the University at Buffalo is still under construction for a mini biography and bibliography. However, site does have an interview of Rita Dove from 1997 and thirteen writings or poems by Dove. Links to other African American...
Lesson Plan
Alabama Learning Exchange

Alex: Let's Make a Pie

For Teachers 9th - 10th
The students will survey their classmates and construct circle graphs to display their results. Students will produce circle graphs using a compass and protractor, and then with an interactive computer program.This lesson plan was...
Handout
Wolfram Research

Wolfram Math World: Equilateral Triangle

For Students 9th - 10th Standards
MathWorld goes into detail about equilateral triangles at this site. Use this site to find out how to construct an equilateral triangle using a compass and straight edge. Learn about the altitude of such triangles, and the rationality of...