**How To Find The Height Of A Triangular Prism**. Usually what you need to calculate are the triangular prism volume and its surface area. The formula for the area of a triangle is 1 2 base × height 1 2 b a s e × h e i g h t, or 1 2 bh 1 2 b h.

The height of an isosceles triangle is calculated using the length of its base and the length of one of the congruent sides. Height of triangular prism given base and volume can be defined as the perpendicular distance between the parallel bases or the length of the altitude drawn to the base of a triangular. B = 1 2 b h b = 1 2 ( 6) ( 4) b = 3 ( 4) b = 12 cm 2.