The Pointed Arch is the first thing that comes to mind when thinking about Gothic Architecture and is necessary for the whole structure to hold. Since Gothic Architecture has become one of the more popular building styles in Minecraft, I want to show you guys how to construct them.

First, you need to lay down the foundation of your structure and mark the ways your Arches are gonna go.
Next, you take the walls or pillars to the hight the Archways start.
Mark the starting points and count the distance, including one ending of the Arch (it's best to use an uneven distance), double it and add the other ending Block. You need to construct half a circle around each ending point (in my case, I'm using a diameter of 21 Blocks (10*2+1) for the smaller one and a diameter of 45 Blocks (22*2+1)for the main one).

Minecraft Circle Generator:
https://donatstudios.com/PixelCircleGenerator

Cut both circles at their intersection and the remainings will leave a perfect Pointed Arch, constructed just like in the 11th Century. You can add Cobblestone Walls to make them look stronger and more realistic.

I hope I've been able to help you and if you want me to do Tutorials on other characteristics of Gothic Architecture, please let me know in the Comments below!