Things You'll Need
Hook and loop tape
Consider pre-fitting the curtain before sewing the bottom hem. This will allow you to make final adjustments before doing the final hem. Some people leave the bottom of the curtain loose so they can adjust their hem to just brush the windowsill.
Angled or trapezoid-shaped windows bring in extra light to a room. These oddly shaped windows with only two parallel sides also draw the eye up and expand the visual space. However, sometimes the windows are oriented so that neighbors can see inside or they are in the path of the sun. Creating attractive curtains for trapezoid-shaped windows isn't difficult and can solve these problems.
Select a curtain fabric that works well with your decor. Trapezoid curtains are fixed in position, so you may wish to choose a fabric in your wall color or a sheer fabric if you are controlling for privacy only. The fabric should be lightweight, as it will be held in place with hook and loop tape.
Prewash and iron your fabric, following the washing and ironing instructions for the type of fabric.
Measure the angled slope of the window. Cut a piece of hook and loop tape to that length and attach the tape to the sloped window framing. Measure the width of the bottom of the window sill. Cut a second piece of hook and loop tape to that length and attach the tape along the bottom of the window sill.
Calculate the finished height of your curtain by measuring the longer vertical side of the window from the hook and loop tape at the top to the hook and loop tape on the window sill. Add 3 inches. Calculate the finished height on the shorter vertical side the same way. Add 3 inches.
Take the width of your window and multiply that amount by 50 percent. Add the result to the width of the window to get your measurement for the width of the curtain. This extra fabric allows the curtain to gather but not be too bulky.
Sew the sides of the curtain to create 1/2-inch hems. Sew the top of the curtain with a 1-inch hem. Sew the matching hook and loop section to the back top of the curtain, gathering the fabric as you sew so that you don't have fabric left over at the end. Hem the bottom of the curtain with a 1-inch hem. Sew the matching hook and loop section to the back bottom of the curtain, gathering the fabric as you sew.
Press the hook and loop tapes together starting at the tall vertical point and working down the slope to the small vertical side. Press the bottom hook and loop tapes together.
F.R.R. Mallory has been published since 1996, writing books, short stories, articles and essays. She has worked as an architect, restored cars, designed clothing, renovated homes and makes crafts. She is a graduate of the University of California at Berkeley with bachelor's degrees in psychology and English. Her fiction short story "Black Ice" recently won a National Space Society contest.