Step 1
Place the arch at the top of the window and mark both countour of the arch with a pencil.
Step 2
Place the side trims at the sides of the window and mark the countor of the trims.
Step 3
Take note of the intersection of the lines you draw for the arch and trims(black circle). Draw anoher line marking the intersection.
Step 4
Place the arch on top of the window again and mark the join lines.
Step 5
Cut the arch and the trims along the join lines that you marked previously and glue them to the wall.
Step 6
Place the trims on the side of the window again and mark the join lines.
