To give a good answer, I would really need to see your mouth, or at least a picture. First thing that comes to mind is an irritation fibroma, which is basically a fancy word for a mouth callous. If a certain spot gets rubbed or abraded or irritated too many times, your body will basically form a callous over the area. Does it wipe off, or is it fixed? Is it a nodule with an obvious beginning and ending to it's borders, or is it sort of a white "zone" blending in with the neighboring tissues? Any white lesion has a potential of being oral cancer. The only way to know for sure is with a biopsy. If you use tobacco, cigarettes, cigars etc then I would get it checked ASAP. Even if yo aren't a tobacco user it could still be cancer. Another simple thing that it could be is a sore/swollen taste bud. We often think of taste buds as being on our tongue, and that is where most of them are, but they are scattered throughout the entire oral cavity including the roof of your mouth, gums, and even throat!. Another simple thing it could be is a tiny salivary gland that is blocked or calcified. there are just too many possibilities.
duodenum or liver
The pancreas is the triangular organ between the stomach and small intestines that produces digestive enzymes. It also has an endocrine function.
The boat was small and had two triangular sails.
At the end of the diamond mine, examine the diamonds with the small magnifier at bottom right. One of the diamonds has a small triangular symbol on it. This is the white jewel, and you can pick it up.
A jib is a small triangular sail.
The meaning of 'push net' is a small triangular net which is used for purposes of fishing. It has a rigid frame and is pushed at the bottom of the water body so as to catch fish.
At the end of the Diamond Mine, you find the white jewel among the diamonds by using the small magnifier at the bottom right. The jewel has a triangular symbol on it. When you see it (third jewel from bottom left), you can pick it up.
triangle
A triangular prism has 5 faces. The size of the prism makes no difference.
Small Triangular shaped pyramids are used in super markets and malls to give them strong support!
At the end of the Diamond Mine, the white jewel is in a pile of diamonds. Use the small magnifier (loupe) at bottom right to examine the diamonds, and you will see one that has an unusual triangular inscription. This is the white jewel, and you can take it. (It is the second one from bottom left.)
It is in the clump of other gems and you can identify it by finding a small triangular shape on it when you use the magnifying glass. It is roughly on the left-hand side, in the bottom corner. Hopefully this helped! :)