We do have some customers who use our made to measure and ready made shade sails as part of their pergolas.
The sides of our ready made shade sails are curved so you need to take into account you wouldn't get a full square/rectangle/triangle shape. If you are looking for a sail with straight edges, this option is available for our Made to Measure Shade Sails.
Please also remember you always need to angle the sail correctly so that when it rains, the water runs off rather than pooling in the middle. If square or rectangle, two of the corners will need to be positioned lower than the others and if a triangle, at least one of the corners. You can find further information in our Installation Guide.
We also have some great pergola shade sail installation photos in our Customer Gallery.