Graphic Organizer/Worksheet


A nice problem that encourages students to think backwards. Instead of inscribing a triangle in a circle, the triangle is given, and the student must discover the diameter of the circle.


  • Mathematics > General
  • Mathematics > Geometry
  • Mathematics > Problem Solving

Education Levels:

  • Grade 6
  • Grade 7
  • Grade 8
  • Grade 9
  • Grade 10
  • Grade 11
  • Grade 12


circumference circle geometry



Access Privileges:

Public - Available to anyone

License Deed:

Creative Commons Attribution 3.0


Update Standards?

CCSS.Math.Content.7.G.B.4: Common Core State Standards for Mathematics

Know the formulas for the area and circumference of a circle and use them to solve problems; give an informal derivation of the relationship between the circumference and area of a circle.
Curriki Rating
On a scale of 0 to 3
On a scale of 0 to 3

This resource was reviewed using the Curriki Review rubric and received an overall Curriki Review System rating of 3, as of 2009-07-03.

Component Ratings:

Technical Completeness: 3
Content Accuracy: 3
Appropriate Pedagogy: 2

Reviewer Comments:

This is a problem for homework or class that requires a flash of insight to complete. Students are asked the size of a circle that circumscribes a given triangle. It turns out that the one angle given for the triangle determines the entire solution. The slightly lower pedagogy rating given is because the author has not gone the extra step of pointing out the generalization or eliciting it from the students.

Not Rated Yet.

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