surface area formula of a prism is:
S.A = 2 × Area of base + Perimeter of base × Height of prism
So the given are:
5 cm, 2 cm, and 3 cm
The base is an equilateral triangle
So the base is 3 cm and height is 2 cm
and we know the area of a triangle is:
A =

P = add all sides together
Substitute them:
S.A = 2 ×

(3)(2) + (3 + 3 + 3) × 5
= 6 + 45
=
51 cm²