Finding cost of a triangular prism
A hollow equilateral triangular prism has a fixed volume of 1.8m^3. The sides of the triangle have length P. To build the prism, one of the triangular faces costs 1.2 times what the remainder of the prism (excluding the base) costs, and the base costs 1.5 times what the remainder of the prism (excluding the previously mentioned triangular face) costs. How can the cost (C) of the prism be expressed in terms of P (the side length of the triangle)? What are the dimensions of the prism if the cost is minimum?