Thank you. Can you please elaborate what you mean by 100% foretriangle?Not quite... A Jib is a 100% (or less) foretriangle headsail.. A genoa is typically a 120 to 155% foretriangle headsail. Both are set and used similarly, with jibs being deployed in heavier air, genoas lighter.
A symmetrical spinnaker is quite different. Colourful, yes.. Usually made of lighter nylon material but it is a 'flying' sail that sets ahead of the forestay usually on a pole.
Cruising spinnakers, drifters, Asails, etc more closely approximate large, light, colourful genoas.. They do not attach to the forestay like jibs and genoas, and don't usually need/use a pole, though short bowsprits are often used.
Hope that helps a bit.
Looking at a sailplan drawing (profile of rig) triangles are formed by the mast, stays, and deck or boom.. If the 'area' of the triangle formed by rig is, say, 100 sq ft, then a 100% jib could also be 100 sq ft... a "155" could be 155 sq ft.Thank you. Can you please elaborate what you mean by 100% foretriangle?