Measure the width of the area you wish to plow. If it is greater than 6 feet wide, divide the area into equal sections of less than 6 feet each. The length of a single section will be the width of your plow.
Measure and cut one 8-foot, 2-by-4 board to the length you determined in Step 1.
Use the Pythagorean theorem to determine the length of the other two sides of your plow. The length from Step 1 is the hypotenuse. The other two sides will be equal to each other because you will be making a 90-degree angle for the front of your plow. For example, if your Step 1 length was 5 feet, the equation would be 5^2 = 2a^2 or 12.5 = a^2. The length of each side would then be the square root of 12.5, or 3.53. Thus, 3.53 feet = 3 feet 6 1/3 inches. This would be the length of each of your two remaining sides.
Measure and cut two 2-by-4s to the length you determined in Step 3.
Cut one end of each of the newly cut sides with a miter saw at a 45-degree angle.
Glue and nail the three boards into a triangular shape with the mitered V in the front.
Nail the 2-by-8 board to the bottom of the miter side of the triangle and the center of the hypotenuse.
Run the open end of the 2-by-8 under a truck with a hitch. Attach it to the hitch with a ratcheting strap.
Weigh down the front end of the plow with sandbags to prevent it from riding on top of the snow instead of plowing through it.