\[ SA = 2(5 \times 8 + 5 \times 10 + 8 \times 10) = 2(40 + 50 + 80) = 2 \times 170 = 340 \, \text{cm}^2 \]

["How to Calculate Area with SA = 2(5 × 8 + 5 × 10 + 8 × 10): A Step-by-Step Guide", "Understanding area calculations is fundamental in geometry, especially when working with composite shapes. One common expression you may encounter is:", "[\nSA = 2(5 \ imes 8 + 5 \ imes 10 + 8 \ imes 10) = 2(40 + 50 + 80) = 2 \ imes 170 = 340 , \ ext{cm}^2\n]", "But what does this formula mean? How is the area of a surface (SA) derived using multiplication and addition? Let’s break it down clearly and explore the logic behind this method.", "---", "### What Does the SA Formula Represent?", "The formula:\n[\nSA = 2(5 \ imes 8 + 5 \ imes 10 + 8 \ imes 10)\n]\nrepresents the surface area of a three-dimensional shape formed by combining rectangular faces. The purpose of multiplying dimensions and adding them inside the parentheses is to calculate the total area of all relevant rectangles composing the shape.", "---", "### Step-by-Step Breakdown of the Calculation", "Start by analyzing each product inside the parentheses:", "- (5 \ imes 8 = 40)\nThis likely represents the area of one rectangular face with sides 5 cm and 8 cm.\n- (5 \ imes 10 = 50)\nThis corresponds to another rectangle with dimensions 5 cm and 10 cm.\n- (8 \ imes 10 = 80)\nMeans another rectangle with 8 cm and 10 cm sides.", "Now, add these areas together:\n[\n40 + 50 + 80 = 170 , \ ext{cm}^2\n]", "Since the formula is multiplied by 2:\n[\nSA = 2 \ imes 170 = 340 , \ ext{cm}^2\n]", "This total represents the combined surface area from all matching rectangular components.", "---", "### Why Multiply by 2?", "In many composite shapes—such as prisms, rectangular boxes, or layered figures—the total surface area arises from identical rectangular faces appearing on both sides. Multiplying the sum inside the parentheses by 2 accounts for this duplication.", "For instance, if the terms inside represent lateral or paired faces, doubling ensures no area is double-counted or missed.", "---", "### Real-World Applications", "This calculation method is widely used when designing:", "- Storage boxes and containers where walls meet at right angles\n- Manufacturing components involving layered rectangular shapes\n- Science and engineering models requiring surface quantification", "By breaking down the shape into measurable rectangular areas and applying symmetry via multiplication, complex surface areas become manageable.", "---", "### Summary", "The formula:\n[\nSA = 2(5 \ imes 8 + 5 \ imes 10 + 8 \ imes 10) = 340 , \ ext{cm}^2\n]\nsimplifies calculating the total surface area of a structured shape using fundamental multiplication and addition. Recognizing how sides combine and prices double offers clarity in both academic study and practical applications.", "Now you’re equipped to apply this logic whenever faced with similar surface area problems—turning complex figures into clear, predictable calculations.", "---", "Keywords for SEO:\narea calculation, surface area formula, composite shape area, SA derivation, geometry problem solving, rectangular prism surface area, math example 340 cm², step-by-step geometry, math practice equations, SA 2×(products), area calculations in cm²", "---", "Expand your geometry knowledge confidently—understanding area formulas opens doors to confident problem-solving in math, science, and design!"]