How to Construct Polygons for Your Minecraft Structures
Most basic Minecraft buildings have rectangular foundations — a simple oneroom structure usually looks like some sort of box. But you want to think outside the box, right? Yeah, you’re probably the creative type.
Building slanted walls
In Minecraft, walls are generally straight because, when you’re building with cubes, you usually place them side by side and on top of one another. But that doesn’t mean that all walls have to be straight — you can construct slanted walls, too.
Check out these three examples of slanted walls. All three are working walls, and they all have a similar design (steps). The wall on the left is composed of single blocks along a diagonal. The walls in the middle and right are the same, except that rather than single blocks, they’re composed of 2block and 3block segments, respectively. This allows you to build steeper and steeper slants.
Constructing polygons with slanted walls
You can make all sorts of shapes by connecting slanted walls at different angles. Here are four different polygons: a diamond, a parallelogram, a pentagon, and a hexagon.
To build polygons like one of these, follow these steps:

Visualize what the polygon will look like.

Build one side.
The rest of the polygon will be built using this side as a guide. Count off the number of blocks if you need to — if the polygon includes another equal side, copy this side exactly.

Complete the other sides of the polygon.
Pay particular attention to sides facing the same direction (parallel) and sides with the same length (congruent).

Fix any mistakes.
If your polygon doesn’t connect exactly right, recheck the length and angle of each side to figure out where the problem is so that you can fix it.
A few common polygons make for truly interesting buildings:

Triangle: Triangles make good bases. A right triangle — essentially a rectangle cut in half — is particularly common because it’s easy to build and integrate with other structures.

Rectangle: Though rectangles are fairly generic building bases, they’re still popular. You can make a rectangle base more interesting by rotating it a little.

Hexagon: A hexagon has six sides — usually three sets of parallel sides. Most are made with 2 normal lines and 4 slanted lines.

Octagon: Eightsided polygons are almost always created with 4 normal lines and 4 diagonal lines. These shapes are good for building large, expansive rooms. You can also build the diagonal sides shorter than the others, to make the octagon look more like a square with its corners chopped off.