Is this a jib? Help

Hey Guys,
Is this some alternate kind of jib, and if so how do you use it? The long edge with connectors for the forstay is about 12 or 13 feet long with the usual dog collar fasteners all along the edge. The shape is a perfect triangle except the bottom edge is slightly curved like a smile going up at the corners. It's much larger than the jib I usually use. This sail came with the boat and I have always avoided it. Any ideas about what you would call this or how to use? I might like to try it out tomorrow (taking off and supposed to be light breezes, so more sail might be better). It might be too long for the forestay - not sure yet.
http://www.flickr.com/photos/43515535@N08/?saved=1
Thank[/img]
Is this some alternate kind of jib, and if so how do you use it? The long edge with connectors for the forstay is about 12 or 13 feet long with the usual dog collar fasteners all along the edge. The shape is a perfect triangle except the bottom edge is slightly curved like a smile going up at the corners. It's much larger than the jib I usually use. This sail came with the boat and I have always avoided it. Any ideas about what you would call this or how to use? I might like to try it out tomorrow (taking off and supposed to be light breezes, so more sail might be better). It might be too long for the forestay - not sure yet.
http://www.flickr.com/photos/43515535@N08/?saved=1
Thank[/img]