Khan Academy
Khan Academy: Circumference of a Circle
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,...
Khan Academy
Khan Academy: Circumference of a Circle
Practice finding the circumference of a circle.
CK-12 Foundation
Ck 12: Trigonometry: Area of a Sector
[Free Registration/Login may be required to access all resource tools.] Find the area of a sector of a circle.
Mathematics Archives
Math Archives: Visual Calculus: Area of a Circle
Students will be able to use The Method of Exhaustion and find the area of a circle by illustrating graphically.
Maths Challenge
Maths challenge.net: Semi Circle Lunes
A lune of a circle is defined and a problem of finding the area of two lunes is given.
Sophia Learning
Sophia: Finding a Formula for the Surface Area of a Cone
This video tutorial demonstrates how to find the formula for the surface area of a cone.
National Council of Teachers of Mathematics
The Math Forum: Ask Dr. Math: Area of a Cone
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.
CK-12 Foundation
Ck 12: Geometry: Area of Sectors and Segments
[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...
CK-12 Foundation
Ck 12: Geometry: Radius or Diameter of a Circle Given Area
[Free Registration/Login may be required to access all resource tools.] Find the radius or diameter of a circle given its area.
CK-12 Foundation
Ck 12: Geometry: Radius or Diameter of a Circle Given Area
[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
Science and Mathematics Initiative for Learning Enhancement (SMILE)
Smile: The Area of a Circle
An investigative approach is given to exploring finding the area of a circle.
Math Planet
Math Planet: Pre Algebra: Measure Areas
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]
Sophia Learning
Sophia: Sector Area of a Circle: Lesson 2
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."
Sophia Learning
Sophia: Sector Area of a Circle: Lesson 4
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."
Sophia Learning
Sophia: Determining Unknown Values Using the Volume of a Cylinder
This video lesson demonstrates how to work backward and use the volume of a cylinder to find an unknown value such as the radius or height. Students can check their understanding with an assessment. [4:41]
ClassFlow
Class Flow: Area of a Circle
[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...
Maths Challenge
Maths challenge.net: Rectangular Circles
An area problem involving finding the area of a rectangle and a circle. The problem may be made into a general proof as well.
Discovery Education
Discovery Education: Web Math: Find Out Things About Circles
This WebMath site will assist with finding the radius, diameter, circumference, and area of a circle.
Texas Instruments
Texas Instruments: Areas of Regular Polygons and Circles
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.
![University of Waterloo: Cemc: Math Circles: 3 D Geometry Ii [Pdf] Unknown Type](https://static.lp.lexp.cloud/images/attachment_defaults/resource/large/FPO-knovation.png "University of Waterloo: Cemc: Math Circles: 3 D Geometry Ii [Pdf] Unknown Type")
University of Waterloo (Canada)
University of Waterloo: Cemc: Math Circles: 3 D Geometry Ii [Pdf]
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.
Varsity Tutors
Varsity Tutors: Hotmath: Review: Area
Find a quick, concise explanation of area and the formulas for different shapes. An example is given to help you understand how find the area of a shape. The area formulas are listed for different types of shapes.
Science Struck
Science Struck: Cross Sectional Area of a Cylinder
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.
Illustrative Mathematics
Illustrative Mathematics: G C Mutually Tangent Circles
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...
Analyze Math
Analyze Math: Overlapping Circles Problem
Try this problem - find the area of the overlapping region of two overlapping circles. You need to find the region of each segment, then add them up. This site gives the problem and a detailed written solution. Good problem for sharp...