Cut four legs, 30 3/4 inches long, from two the two 1-by-8 pieces of wood. Miter the tops and bottoms by 22.5 degrees. Then cut two cross braces, both 30 1/2 inches long, and angled at 22.5 degrees using a chop saw. Cut two lower 54 1/4 inch braces without any angles.
Put together both the left and right A-frames. Take the legs and lay them on a flat surface so the bottoms are 51 1/2 inches apart. Then place the lower cross brace on top of the legs and place the lower cross brace across the legs about halfway down. The lower cross braces should stick out beyond the legs equally on both sides. Hold the pieces together with clamps and hammer nails partway to hold them in place.
Drill four holes to fasten the A-frame. Each hole should be 1-inch wide and 1/2 inch deep. Use bolts, washers and nuts to fasten the pieces together.
Construct the benches by taking one of the A-frames and connecting two 2-by-4-by-6 pieces of wood to each side. They should be placed on top of the lower cross braces and connected with 2 1/2 inch deck screws. Repeat this step with the other A-frame.
Attach the top of the table to the A-frames by securing four 1-by-8-by-6 pieces of wood with 1 1/2-inch deck screws.
Cut a 2-by-4-by-6 piece of wood 29 inches long to make a bottom support brace. Miter each end at 22.5 degrees. Place the board in the center of the table top and attach using 2 1/2-inch screws. Build two 8 inch long seat braces by cutting a 2-by-4 piece of wood. Place them underneath in the center of the seat and attach with 2 1/2 inch screws. Then take another 2-by-4 and cut two 31-inch pieces to be used as angle bracing. Use a chop saw to cut both ends at 28 degrees. Use 2 1/2 inch screws to attach to the lower cross braces and the bottom support brace.
Paint or stain picnic table as desired.