Take a tape measure, and measure head to foot along both luff (front) and leech (rear)
then tack to clew along the foot. (Google these terms if you are new to sailing).
Describe condition...any rips or tears or broken pockets?
Post details in the "items for sale" on this Forum, plus of course the pictures.
Sounds like these were from a Hobie 16.
Folks on this Forum will guide you re pricing.
1989 Hobie SX18 Sail # 1947
'Only two things are infinite, the universe, and human stupidity. But I'm not sure about the former.'