Determine the size of the desk that is needed. This will determine the width of the door that is required. The door can be 24, 36 or even 48 inches wide. It can be a hollow or solid door.
Using the tape measure, make a mark at the length that is the same as the width of the door. If the door is 24 inches wide, measure 24 inches in length.
Using a ruler, draw a line from the marked measurement to the opposite end at the bottom of the door. This is done to create a perfect triangle.
Using the saw, cut along the line you have made. This is one of the edges that will go against the wall.
Mark the 2 by 4-inch piece of wood the same measurement as the width of the door. Cut with the saw. Mark another 2 by 4-inch piece of wood the same length minus 1" and cut this piece with the saw. These pieces will hold up your corner desk.
Locate the studs and mark. Place wood glue on the side of the 2 by 4-inch wood pieces that will go against the wall. Put into place and screw the two2 by 4-inch pieces of wood into the marked studs on the wall. Put wood glue on top of these installed pieces of wood. Place the triangular cut piece of door on top of the two installed pieces of wood on the wall and screw in with wood screws.
Stain or paint the wood the desired color. Use a sealer if desired.