\( SA = 2(40 + 96 + 60) = 2 \times 196 = 392 \) square centimeters.

["How to Calculate Area: Solving ( SA = 2(40 + 96 + 60) = 392 , \ ext{cm}^2 ) in Easy Steps", "When calculating the surface area (often denoted ( SA )) of a three-dimensional shape, understanding the formula and how to apply it is essential—for beginners and professionals alike. One such calculation is ( SA = 2(40 + 96 + 60) = 392 , \ ext{cm}^2 ). This equation demonstrates the key principle of finding the total surface area of a rectangular prism by summing the areas of all its faces and doubling the total.", "### What is Surface Area?", "Surface Area (SA) measures the total area that the surface of a three-dimensional object occupies. For objects like boxes, prisms, or cubes, this involves adding up the areas of all six faces—though in complex shapes, grouping opposite faces can simplify calculations.", "### The Formula in Action", "The formula for the surface area of a rectangular prism is:", "[\nSA = 2(lw + lh + wh)\n]", "Where:\n- ( l ) = length\n- ( w ) = width\n- ( h ) = height", "In your example, the sum inside the parentheses ( (40 + 96 + 60) ) represents three unique face areas combined:", "- Area 1 = ( 40 , \ ext{cm}^2 )\n- Area 2 = ( 96 , \ ext{cm}^2 )\n- Area 3 = ( 60 , \ ext{cm}^2 )", "Multiplying this total by 2 accounts for the fact that opposite faces on a rectangular prism are identical. Thus,\n[\nSA = 2 \ imes (40 + 96 + 60) = 2 \ imes 196 = 392 , \ ext{cm}^2\n]", "### Why Multiply by 2?", "Each rectangular face has a corresponding opposite face with the same area. By summing three unique faces and doubling the result, you ensure that every surface is counted exactly once, avoiding double-counting and mathematical error.", "### Real-World Applications", "Understanding this formula is vital in fields such as engineering, packaging design, construction, and graphic arts. Accurate surface area calculations help optimize materials, estimate costs, and ensure product precision.", "### Step-by-Step Summary", "1. Identify dimensions: Determine length, width, and height.\n2. Calculate face areas: Compute ( lw, lh, wh ).\n3. Sum the areas: Add all three face areas.\n4. Multiply by 2: Double the total to get total surface area.\n5. Verify units: Ensure all measurements are in consistent units (e.g., centimeters) for correct area in square centimeters.", "### Final Calculation", "[\nSA = 2(40 + 96 + 60) = 2 \ imes 196 = 392 , \ ext{cm}^2\n]", "This simple arithmetic method efficiently delivers the correct surface area—showcasing how foundational math underpins practical problem-solving in daily life and technical fields.", "---", "Keywords: Surface Area formula, rectangular prism surface area, ( SA = 2(40 + 96 + 60) = 392 , \ ext{cm}^2 ), how to calculate surface area, rectangular prism calculation, area calculation, geometry principles, math tutorial, practical geometry.", "Meta Description: Learn how to calculate surface area using ( SA = 2(40 + 96 + 60) = 392 , \ ext{cm}^2 ). Step-by-step guide for students, teachers, and DIY enthusiasts—perfect for understanding arithmetic in 3D geometry."]