Unit Plan
CK-12 Foundation

Ck 12: Geometry: Radius or Diameter of a Circle Given Area

For Students 6th - 7th
[Free Registration/Login may be required to access all resource tools.] Find the radius or diameter of a circle given its area.
Unit Plan
CK-12 Foundation

Ck 12: Geometry: Radius or Diameter of a Circle Given Area

For Students 7th
[Free Registration/Login may be required to access all resource tools.] Find the radius or diameter of a circle given the area of the circle
Activity
Mathematics Archives

Math Archives: Visual Calculus: Area of a Circle

For Students 9th - 10th
Students will be able to use The Method of Exhaustion and find the area of a circle by illustrating graphically.
Activity
Discovery Education

Discovery Education: Web Math: Find Out Things About Circles

For Students 9th - 10th Standards
This WebMath site will assist with finding the radius, diameter, circumference, and area of a circle.
Unit Plan
Khan Academy

Khan Academy: Circumference of a Circle

For Students 6th - 8th
Find the circumference of a circle when given either the radius or diameter.Find the radius or diameter of a circle when given the circumference.Students receive immediate feedback and have the opportunity to try questions repeatedly,...
Unknown Type
Khan Academy

Khan Academy: Circumference of a Circle

For Students 7th Standards
Practice finding the circumference of a circle.
Unit Plan
CK-12 Foundation

Ck 12: Trigonometry: Area of a Sector

For Students 10th - 12th
[Free Registration/Login may be required to access all resource tools.] Find the area of a sector of a circle.
Activity
Oswego City School District

Regents Exam Prep Center: Circles: Area of Sectors and Segments

For Teachers 9th - 10th
Material to supplement classroom instruction on sectors and segments of circles. Find guidelines on how to find the area of sectors and segments, as well as a multiple-choice quiz, and an activity idea called "Sectors and Pizza."
Unit Plan
Sophia Learning

Sophia: Sector Area of a Circle: Lesson 2

For Students 9th - 10th Standards
This lesson will demonstrate how to find the area and radius of a circle when given the sector area and central angle measure. It is 2 of 8 in the series titled "Sector Area of a Circle."
PPT
Sophia Learning

Sophia: Sector Area of a Circle: Lesson 4

For Students 9th - 10th Standards
This lesson will demonstrate how to find the area and radius of a circle when given the sector area and central angle measure. It is 4 of 8 in the series titled "Sector Area of a Circle."
Unit Plan
National Council of Teachers of Mathematics

The Math Forum: Ask Dr. Math: Area of a Cone

For Students 9th - 10th Standards
This question and answer site is about finding the area of a cone when the height and the angle at the convergence point are given. The site goes on to explain how a cone relates to a circle.
Activity
National Council of Teachers of Mathematics

The Math Forum: Find the Area of the Shape!

For Students 3rd - 8th Standards
Try to figure out the area of this challenging shape. In order to view the images, you will need to use JavaSketchpad.
Unit Plan
CK-12 Foundation

Ck 12: Geometry: Area of Sectors and Segments

For Students 9th - 10th
[Free Registration/Login may be required to access all resource tools.] In this lesson students find the area of a sector or segment. Students examine guided notes, review guided practice, watch instructional videos and attempt practice...
Activity
Maths Challenge

Maths challenge.net: Semi Circle Lunes

For Students 9th - 10th Standards
A lune of a circle is defined and a problem of finding the area of two lunes is given.
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University of Waterloo (Canada)

University of Waterloo: Cemc: Math Circles: 3 D Geometry Ii [Pdf]

For Teachers 9th - 10th Standards
This worksheet provides a variety of 3D geometry questions requiring higher order thinking skills. Questions include; finding the surface area of a prism, surface area of pyramid, surface area of a sphere, and platonic solids.
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.
Whiteboard
ClassFlow

Class Flow: Area of a Circle

For Teachers 6th - 8th Standards
[Free Registration/Login Required] This flipchart reviews basic geometric forms in nature and real objects. Students are then given opportunities to find the area of circle and parts of a circle, given the radius and/or diameter of the...
Handout
Science Struck

Science Struck: Cross Sectional Area of a Cylinder

For Students 6th - 9th
Presents the formula and an example showing how to find the cross-sectional area of a cylinder. In this case, it is the same as the surface area for the circular faces.
Activity
Texas Instruments

Texas Instruments: Areas of Regular Polygons and Circles

For Teachers 9th - 10th Standards
Use Cabri Jr. to find the area of several regular polygons and then use that investigation to derive the area of a circle from a many-sided polygon.
Lesson Plan
Science and Mathematics Initiative for Learning Enhancement (SMILE)

Smile: The Area of a Circle

For Teachers 6th - 8th Standards
An investigative approach is given to exploring finding the area of a circle.
Unknown Type
Common Core Sheets

Common Core Sheets: Geometry 7.g.4 Worksheets: Area and Circumference Circle

For Teachers 7th
Worksheets provide practice with finding the area or circumference of a circle and answer keys are provided. You can even create your own worksheet or flashcards.
Unit Plan
Math Planet

Math Planet: Pre Algebra: Measure Areas

For Students 4th - 6th Standards
Demonstrates how to calculate the area of two-dimensional shapes using formulas. Covers parallelogram, triangle, trapezoid, and circle. Includes a video modeling how to find the area of a circle and a triangle. [0:59]
Unit Plan
Khan Academy

Khan Academy: Area and Parts of Circles

For Students 6th - 8th Standards
Practice finding the area or circumference of part of a circle. Students receive immediate feedback and have the opportunity to try questions repeatedly, watch a video or receive hints.
Lesson Plan
Illustrative Mathematics

Illustrative Mathematics: G C Mutually Tangent Circles

For Teachers 9th - 10th Standards
Three circles are mutually tangent. Students are asked to find the total area of the circles plus the area inside where they meet. Students will need to know how to calculate the area of a circle, a sector of a circle, and an equilateral...