A circle chart is a diagram used as guidelines when making circles. It can be used for lighthouses, corner towers on castles, or anytime you need a circle in a square world.If you want to build a sphere or dome, there are several ways you can do this. The first is to create a circular frame that outlines all vertices with the largest circle (see example). After that is complete, you simply fill in the excess area with circles on scale with the layer that it is on.
If you are having problems making circles when building something you can use the image below to help you. You can find a lot of helpful videos in Youtube but if you have some experience building this circle chart may be all you need to start your building. As you know the game is “squared based” so making a perfect circle it’s pretty much impossible but playing Minecraft is about figuring out how to build with what you have so the circle blueprint is maybe the easiest way to do it.