👉 A prism is a three-dimensional figure that has two congruent polygonal bases and one curved surface. In geometry, prisms are characterized by their base, which is typically a polygon with four sides. The lateral faces of a prism are triangular in shape, which can be either right or oblique (or sometimes both), depending on the position of the vertices. The term "prism" comes from the Latin word "prismus," meaning "two-sided." This name reflects the fact that