Measure the wall horizontally starting at the corner of the room to the edge of the window using a tape measure. Then use the tape measure to find the measurements starting from the ceiling to the floor.
Attach a full sheet of drywall starting at the corner. Continue until you reach the sheet you need to measure the wall.
Place a full sheet of drywall on a flat surface. Transfer your measurements onto the drywall. If the drywall doesn’t extend to the end of the window, draw an “X” on the area of wallboard you don’t need.
Put a straightedge against the drywall, then repeatedly score or cut it, using a utility knife. Snap off the portion of the drywall you don’t need.
Stand the sheet of drywall up, then use a handsaw to make the cuts to the arch. Depending on the size of the window, you may have to use two sheets of drywall to cover one side of the window.
Attach the drywall using drywall screws and drill. Repeat the process on both sides of the window.
Start in the corner of the room and attach full sheets of drywall using a drill and drywall screws. Repeat until you get to the arched window.
Place a full sheet of drywall over the bottom half of the window opening. Secure the drywall with drywall screws.
Use the window’s frame as a guide to cut the drywall from top to bottom with a handsaw. Score the bottom of the drywall where the window sill is, using a utility knife. Pull the drywall towards you until the portion snaps off.
Attach drywall to the top of the window. With a handsaw, cut around the arched window until you’re able to remove the portion you don’t need.