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
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.] This concept teaches students to apply the Intersecting Chords Theorem to solve for missing segments from chords.
Unit Plan
Cuemath

Cuemath: Central Angle

For Students 9th - 10th Standards
Learn all about the basic properties of central angles. This lesson targets what is a central angle, central angle formula, central angle calculator, theorem of central angle, how to find central angles, and how to apply them while...
Activity
Analyze Math

Analyze Math: Inscribed and Central Angles in Circles

For Students 9th - 10th Standards
The geometry tutorial investigates the definitions and theorems related to inscribed and central angles in circles. An example with a detailed solution is included.
Handout
Geometry Help

Geometry Help: Chords

For Students 9th - 10th Standards
Explains the basic concept of chords with step-by-step instructions and methods for solving specific problems on your own relating to this topic.
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
Geometry Help

Geometry Help: Arcs, Angles, and Sectors

For Students 9th - 10th Standards
Explains the basic concept of arcs, angles, and sectors with step-by-step instructions and methods for solving specific problems on your own relating to this topic.
Handout
Geometry Help

Geometry Help: Tangent Lines

For Students 9th - 10th Standards
Explains the basic concept of congruent triangles with step-by-step instructions and methods for solving specific problems on your own relating to this topic.
Unit Plan
Khan Academy

Khan Academy: Inscribed Angle Theorem Proof

For Students 9th - 10th Standards
Proving that an inscribed angle is half of a central angle that subtends the same arc.
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...
Website
Cool Math

Coolmath: Precalculus Basic Formulas to Know

For Students 9th - 10th Standards
This CoolMath resource provides an introduction to some Precalculus formulas.
Handout
Oswego City School District

Regents Exam Prep Center: Formulas for Angles in Circles

For Students 9th - 10th Standards
Formulas and illustrations show the different kinds of angles created by intersecting tangents, secants, radii, and in combination.
Unit Plan
Khan Academy

Khan Academy: Challenge Problems: Inscribed Angles

For Students 9th - 10th Standards
Solve two challenging problems that apply the inscribed angle theorem to find an arc measure or an arc length.
Activity
Other

Edumat: Geometria Interactive

For Students 9th - 10th
In this section different interactive activities are presented which can be used as supplementary material to traditional classroom and allow for interactive study of mathematics.
Lesson Plan
Other

Ctte: Geometer's Sketch Pad Activities

For Teachers 9th - 10th
This site offers numerous activities for middle school and high school students to explore using Geometer's Sketch Pad.