Constructor 1

How to Inscribe a Octogon in any Circle

video tutorial part
7
of

Learning Geometry with a Circle Arc Template

with

Chris Tisdell

Mathematician & Educator
Chris Tisdell
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Materials you will need:

Constructor 1 Template
Unlined Paper / Scrap Paper
Sharp Pencil/s
Fine-point Pen/s
Eraser

What you will learn in this tutorial:

Creating an octagon inside a circle is a fun and achievable task with the help of Chris Tisdell and a circle arc template.

We begin with a circle whose centre point is known. Chris starts by drawing two diameters across the circle, and they meet at the very centre. These lines are special because they're perpendicular to each other.

Now, these two lines we just made represent half of the vertices of our octagon. Think of them as two corners of an eight-sided shape.

Next, we create more lines to complete our octagon. Chris shows us how to bisect two of the angles formed by the two perpendicular diameters. Bisection is dividing something into two equal parts. By bisecting these angles, we're creating two more lines that go through the centre of the circle.

Now, with these additional lines in place, we have four lines inside the circle, and they all meet at the centre.  Here's where the magic happens. The points where these four diameters meet the edge of the circle become the corners of our octagon. Imagine these points as dots around the circle's edge, evenly spaced apart.

To complete our octagon, we need to connect these points. Chris does this by drawing eight line segments. Each line segment connects one dot to its neighbouring dot, forming the sides of the octagon.

As you follow along with these steps, you'll see the octagon taking shape inside the circle. It's like connecting the dots to reveal a hidden picture.

Now, to make sure we've done it correctly, we can check a few things. First, we want to make sure all the sides of our octagon are the same length. You can measure them with a ruler to confirm.Then, you can also check the angles at each corner to see if they're all equal.

In the end, inscribing an octagon within a circle is a bit like solving a puzzle. You start with a circle and use these clever geometric tricks to create an octagon inside it. Chris Tisdell's method, using the circle arc template, makes this process simpler and more accessible for anyone interested in geometry.

So, if you ever want to impress your friends with your geometric skills or simply enjoy exploring shapes and patterns, grab a Mathomat and give it a try! You'll discover that geometry can be both fun and fascinating.

Chris Tisdell

Chris Tisdell

Mathematician & Educator
Chris, a mathematician and educator, is an academic advisor to Mathomat. Chris approached us in 2021 with an interest in the circle templates in Mathomat...
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