Use a table saw and cut out a 1-inch thick sheet of Plexiglass, measuring 3-by-6 feet. This is the desk top.
Cut two sheets of Plexiglass, 3-by-3 feet. These are the desk's legs.
Measure in 1 1/2 feet from the edge of one side of the desk top. Position the first leg in 1 1/2 feet, perpendicular to the desk top. Drill four screws through the desktop into the leg to attach it. The screws should each be 6 inches apart from each other, and from the edges of the desk top.
Measure in 1 1/2 feet from the edge of the other side of the desk top. Position the second leg in 1 1/2 feet perpendicular to the desk top, parallel to the other leg. Drill four screws through the desktop into the second leg to attach it, same as the first.
Stand the desk up so the feet are on the ground.
Apply a Plexiglass repair kit solution to the top of the screw. This fills the indentation left by the screws in the desk, and restores a smooth finish.