Mathematics-Geometry-17

There is a famous Greek chocolate bar that is molded in the shape of a triangular prism. A couple wants to give out these bars to some friends, but wanted to re-wrap the sides, not the ends, in their own design. If the triangles on the end are equilateral with a side length of 3 cm, and the length of the bar is 15 cm, what will be the area of their custom wrap be?