A prism is a polyhedron with two parallel faces called bases. The other faces are always parallelograms. The prism is named by the shape of its base
• Surface Area = 2 × Area of base shape + Perimeter of base shape × height
• Volume = Area of base shape × height of prism
In case of a triangular prism, the area of the base triangles can be found out by :
(i) A = \(\frac12\) x b x h, if base (b) and altitude (h) of the triangle are known.
(ii) A = \(\sqrt{s(s-a)(s-b)(s-c)}\), if all three sides a, b, c are known where s = \(\frac{a+b+c}{2}\)
(iii) A = \(\frac{\sqrt3}{4} a^2\), if the bases are equilateral triangles of side ‘a’.
A prism is a regular prism if its bases are regular figures, i.e., with sides equal, i.e., equilateral triangle, square, regular hexagon, etc.
Note : Area of a regular hexagon = \(\frac{\sqrt3}{4} (edge)^2.\)
