How to find the center of any given circle - Maker Math #1

Maker Math #1 - One of the methods I use to find the center of any given circle.

This is the first of a series of math based videos meant for Makers.

The Maker Math series will provide math tricks that convey ideas about the nature of shapes, materials, and measurement.

These principles can be used for any category of craft.

I hope to share my knowledge of geometry and other applicable math to help anyone interested in increasing their ability to make things.

#makermath


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WARNING:
This video is only for entertainment purposes. If you rely on the information portrayed in this video, you assume the responsibility for the results. Always think ahead. Every project you try is at YOUR OWN RISK.

[-th_CAV]

You did a good job of explaining how to find the center point. I think you omitted a critical piece of information. You mentioned that the distance between the points of the compass are arbitrary, which is true. However, that distance does have one requirement. It must be greater than one-half the diameter of the circle. If the scribed arcs are less than or equal to the radius of the circle you will not be able to draw an intersection of those arcs.

[grandolddrummer]

A quicker way to do this is to use your framing square to inscribe a right triangle in your circle. The hypotenuse will always be a diameter. Because an inscribed angle of 90 has a central measure of 180. Draw two different diameters and presto, you've got the center located. No compass necessary.

[stoneblue]

OR make a square (line) around the circle, just touching the outer rings on paper.
Draw a box around the circle, and now just X the box corner to corner with lines to find center.

[jerrycatanese]

by far the best example i've seen or used! Thank you!

[stxxcrisler]

Specifically, what compass are you using? It looks great, accurate, and highly adjustable! It can't be that Alvin you have listed.

[WilliamLutesMaker]

Do more, many more !!!!Make darker lines tho, was a bit hard to see.Bravo Brother :-)

[djones]

I need a way to mark the centre of a rod onto a flat surface.
It's a floating shelf bracket with steel tubes welded at a certain distance apart.
So I need to know precisely where the centres are and mark that on the edge of the shelf.

[sticknstonesbrkbones]

Learned that back in high school. I used it a lot since then. Surprising because most things I learned in school have zero use in the real world.

[CondredgeDole]

love this stuff! now to remember it for when I need it.

[bocfus]

Thanks for sharing this, I like to learn new things and you just helped me with a problem and gained a new sub, keep up the great work!

[matts.]

Or trace the circle on paper like that. Carefully cut the circle out and then fold the paper in half each way. Where the folds meet is the center

[JackSmith-bysb]

Gotta remember that!! I think I learned that in drafting, but totally forgot!

[carlrsxs]

Another way to do it, might be a bit less precise but faster. Draw a straight line through the circle just like you did, but instead of using a compass, you can find the middle of that line inside of the circle. Then you trace a 90degre line right on the middle you just found. Repeat that process with a second random line throught the circle and your two 90degre lines will cross right in the middle of the circle.

[noname-sieg]

Thank you very muchhh.. You help me a lot

[shanetyree]

just fold the paper so the circle is divided in half by lining up the two half circles on top of each other. this will give a line right down the center if the circle. Now fold it again at a right angle to the first by lining up the first folds and circle halves on top of each other and there is your center. No need for compasses and all that fancy geometry.

[johnrobinson]

Can't see the lines drawn by the compass.

[Mikepservice]

Sounds like too much trouble, I think I'll eyeball it lol. But good video, thanks

[plainlogic]

A much easier method is to draw 4 arcs with the compass. Adjust the compass to mak an arc from the radius of the circle to a little past the imagined center of the circle. Draw n arc from the 3, 6, 9, and 12 o'clock positions( close enough is good enough ..As perfect circle has an infinite amount of points around the circumference).
Lastly draw a line using the straight edge through the opposite interesting arcs. The line intersection will always center of the circle.

You can also try to intentionally miss align the 4 points along the radius and it will still work out...
GOOD DAY!

[alanmustarde]

I am sure that you are right in theory, but as we cannot see your lines clearly you are of little help.