What are the calculations and formulas shown in the image?

The image contains calculations related to the volume and surface area of a rectangular prism (or cuboid). Here are the formulas and calculations as written:

• Volume (V):
• Formula: V = a · b · c
• Calculation: V = 3 · 4 · 5 = 60 (cm^3)
• Surface Area (S):
• Area of two sides (S₁): S₁ = 2 · a · b = 2 · 3 · 4 = 20 (cm^2)
• Area of another two sides (S₂): S₂ = 2 · b · c = 2 · 4 · 5 = 20 (cm^2)
• Area of the base (Sₐₙₓ): Sₐₙₓ = (a · c) · 2 (The formula in the image seems to be incomplete or a simplification. It shows S_ocn = ... which likely stands for S_основной, meaning base area.)
• Total Surface Area (Sₙₙₙ): Sₙₙₙ = 2 (S₁ + S₂ + Sₐₙₓ) (This formula represents the sum of the areas of all six faces of the prism.)

Note: The values for a, b, and c appear to be 3, 4, and 5 respectively, based on the calculations.