Put the safety glasses on. Cut both ends of both 36-inch boards using the compound miter saw at a 45-degree angle. When the board is on edge, it should look like a trapezoid. Cut the 51-inch board in the same manner.
Run a bead of glue along the angled ends of the 36-inch boards and clamp the ends together so they make a 90-degree angle. Run a bead of glue on the edges of the 51-inch board, and clamp it to both 36-inch boards so you have two 45-degree angles between the three boards. Let the glue dry. This is the table's frame.
Remove the clamps. Drill two 3/32-inch pilot holes through each of the three corners to prepare to screw the boards together. This will provide extra durability. Drill a 1/4-inch-deep 3/8-inch hole into each 3/32-inch pilot hole. Screw into the holes.
Position a 30-inch board in each of the corners. The ends of the boards should be flush with one side of the frame. The board that fits in the 90-degree corner will fit tightly; however, there will be a gap between the 45-degree corners and the other two boards. Make sure they are as tight as they can be, and that they are flat on the 51-inch board. Drill pilot holes and 1/4-inch deep 3/8-inch holes, and screw four screws through each corner of the frame and into the boards.
Cut the walnut veneer plywood from corner to corner with the circular saw. You should have two triangular pieces. Place both pieces on top of the frame so the edges of both are flush with the sides of the frame. Drill two 3/32-inch holes through each side of the plywood and into the frame. Drill a 1/4-inch-deep 3/8-inch hole into each 3/32-inch hole. Screw the plywood to the frame.
Apply wood putty to the holes surrounding the wood screws. Let it dry and sand the table with the medium- and then fine-grade sandpaper. Wipe the table clean with the tack cloth and apply the wood stain.