Geometry of a Circle

ETC Montessori

Price: $120.00
5.90 LBS
CPSIA Exempt
Available on:
Combination Acrylic & Plastic; Cut
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Product Overview

  • No Lamination Required.
  • Printed on Premium Thick Plastic and Cut.
  • This material is ready to start using. No other prep work is needed.

Considered a symbol of the divine symmetry and balance in nature, the circle was one of the most revered and fascinating geometric shapes. Greek mathematicians were enthralled by the geometry of circles and explored their properties for centuries. This highly symmetrical shape is unique in that every line through the center forms a line of reflection symmetry. A world without circles would surely be a very "square" world!

Where algebra meets geometry, one can find the foundations and properties of a circle. Conics are the graphical interpretation of a circle being cut by a plane. If the plane crosses the circle perpendicular, then it's a circle that is formed on a coordinate plane. If it's crossed at an angle, then the resulting shape on the coordinate plane is an oval or even a parabola. 

This curriculum forms the foundation of moving from geometric reasoning to algebraic thinking and it is intended for higher upper elementary students to middle school. Everything you will need is included in a self-contained wooden box with a lid.


  • Self-contained in a wooden box with lid
  • 20 Acrylic circles for hands on explorations
  • Acrylic lines
  • Cork backing
  • 52 Activity/research cards printed on plastic and cut
  • Protractor
  • Ruler with metric and customary units
  • Answer key provided online

Explorations and work are provided to allow students to work on the following concepts. Each concept is color coded for ease of identification:

  • General Area of a circle
  • Area of a sector of a circle
  • Area of a segment of a circle
  • Area of an annulus
  • Finding the arc of a circle
  • Understanding tangents of a circle

Additional concepts and explorations in:

  • Circumference
  • Diameter
  • Radius
  • Semi circumference
  • Chord
  • Triangles
  • Semicircle
  • Arc
  • Minor arc
  • Major arc
  • Minor section
  • Major section
  • Minor segment
  • Major segment
  • Lines
  • Tangent lines
  • Perpendicular lines


Teacher's Notes and/or Answer Key

Look at our Upper Elementary Geometry Flow Chart to see how this work fits in with the traditional Montessori geometry curriculum. This material may also be used in Level 12-15 Montessori Middle School. 

View the Standards that are met through this material.


Container is included