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Interactive
Mangahigh

Mangahigh: Shape: Radius and Tangent Rule for Circles

For Students 9th - 10th Standards
Determine the rules for radius and tangents of circles.
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Activity
CK-12 Foundation

Ck 12: Tangent Lines

For Students 9th - 10th
[Free Registration/Login Required] Students can adjust the size of the circle to explore the tangent lines. Click learn more to watch a video and click challenge me to answer a practice question.
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Activity
CK-12 Foundation

Ck 12: Segments From Secants and Tangents

For Students 9th - 10th
[Free Registration/Login Required] Students will adjust points to explore secants and tangents of circles. Click learn more to watch a video and click challenge me to answer a practice question.
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Interactive
Mangahigh

Mangahigh: Pyramid Panic: Basic Shapes to Advanced Geometry

For Students 9th - 10th Standards
Guide a mummy safely through the burial chambers of a pyramid as you solve length and area problems in basic to advanced geometry. There are four game zones that deal with circles and triangles, quadrilaterals, the Pythagorean Theorem,...
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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.
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Whiteboard
ClassFlow

Class Flow: Circles Geometry

For Teachers 6th - 8th Standards
[Free Registration/Login Required] Students identify segments and lines related to circles and the properties of a tangent to a circle.
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Activity
Ministerio de Educacion, Cultura y Deporte (Spain)

Cnice: Relacion De Ejercicios Interactivos.

For Students 9th - 10th
In Spanish. Interactive activities online on various geometric and trigonometric concepts such as area, perimeter, secants, tangents, etc. A terrific resource for students. Site is organized acoording to shape. (triangle, quadrilaterals,...
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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.
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Unit Plan
Khan Academy

Khan Academy: Challenge Problems: Circumscribing Shapes

For Students 9th - 10th Standards
Solve two challenging problems that apply properties of tangents to find the perimeter of a circumscribing shape.
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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.