This question was previously asked in

DSSSB PRT Subject Concerned Official Paper - 15 Nov 2019 Shift 1

Option 1 : Prism

Triangular Prism is 3-D body shown in the following figure:

**It has the following features: **

- It has 2 triangular faces (one at the top and one at the bottom). We usually name those as the
**bases**. - Further it has 3 rectangular faces each of which is perpendicular to the triangular end. These surfaces are known as
**lateral faces**. - The distance between the two triangular ends is known as the height of the prism (it is also said as the length of the prism when lies horizontally).

**NOTE:**

**Let us review some other formulae regarding prism:**

- Lateral surface area = h × perimeter of the base
- Area of the ends = 2 × area of each end.
- Total surface area of a prism = lateral surface area + area of the ends = h × perimeter of the base + 2 × area of each end.
- Volume of a prism = base area × height.

**Hence, it can be concluded that PRISM has two triangular faces (one at the top and one at the bottom) generally known as bases and three rectangular faces perpendicular to the triangular end.**