Circular Structures


In this lesson students will use their basic understanding of circles to learn how circular structures are built. The example shown is that of the Roman Colosseum. Students will construct an oval shape from circular arcs to simulate the elliptical shape of the Roman Colosseum.

For this lesson make sure that students have ready access to a compass, ruler, grid paper (graph paper with x-y axes marked is preferred), and pencil with an eraser. The first construction has students creating a teardrop shape from circular arcs that have overlapping points of tangency. This first construction sets up the more elaborate second construction.

Students then look at a real-world application of using circular arcs to approximate the elliptical shape of the Roman Colosseum in a highly engaging video. Students analyze the architecture of the Roman Colosseum and are then shown how to build a scale model of the interior of  the Colosseum.

This lesson can be assigned to individual students or teams of students. The lesson can be completed in about 20 to 25 minutes. 

Math Concepts

  • Geometric Constructions
  • Circles

Learning Objectives

  • Define the terms circular arc and tangent
  • How to construct circular shapes using circular arcs
  • How to analyze the architecture of circular structures

Prerequisite Skills

  • Basic knowledge of circles
  • How to use a compass
Lesson Duration 20 mins
Grade Range 8th - 10th Grade

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