Three-dimensional arch puzzle

A method of making an arch comprising steps of:

• providing an arch puzzle comprising:
• a base comprising a substantially flat upper surface, a first ridge protruding upward from the upper surface at a first side, and a second ridge protruding upward from the upper surface at a second side, wherein a notch is defined therebetween;
• an arch support having a semi-circular block shape;
• a plurality of arch pieces having a keystone shape;
• and
• at least a first pair of shims each comprising an elongated body having a length, a width, and a depth, the depth gradually increasing from a first end to a second end defining a sloped upper surface and a horizontal lower surface;
• placing the sloped upper surfaces of the first pair of shims against each other to form a rectangular cuboid shape and placing the pair of shims on the substantially flat upper surface in the notch;
• placing the arch support on top of the pair of shims;
• placing each of the plurality of arch pieces along an upper edge of the arch support forming an arch with the plurality of arch pieces;
• and
• pulling the pair of shims out from underneath the arch support.