Measure and mark two 2-inch-by-6-inch-by-8-foot boards into three pieces each 45 inches long. Measure and mark a 2-inch-by-4-inch-by-10-foot board into four 15-inch pieces (legs) and four pieces at 12 inches (leg braces).
Put goggles on. Set up a circular saw. Cut along the marked areas on the wood.
Take one of the 45-inch boards and draw a freehand arch that is 3 inches high at the center. Set up a jigsaw and cut along the arch.
Sand all cut surfaces of the wood with 80-grit sandpaper.
Stack two leg braces on top of one leg and line up edges. Drill through all pieces of wood with a 3/8-inch drill bit. Repeat the process with the other three legs. Place one of the leg braces on a flat surface and run a carriage bolt up through the hole. Add to this one of the legs and top with another leg brace. Repeat with the other three legs, and don't tighten the bolts until both legs have been attached to a set of braces.
Stand up leg frames 36 inches apart with the threaded end of the bolts facing inward. Place the arched piece of wood on top of the leg frames, lined up with the back edge of the top. Secure with 3-inch-long deck screws by going through the top and into the leg frames. Repeat with the remaining top pieces.
Sand the whole project with 240-grit sandpaper. Apply finish if desired.