If a rectangle has length 10 cm and width 4 cm, its area is:

**The reasoning** The area of a rectangle uses this simple formula: **Area = length × width** You're given: - Length = 10 cm - Width = 4 cm So: Area = 10 cm × 4 cm = **40 cm²** That's it! Area means "how much space is inside" the shape. Imagine covering the rectangle with 1 cm × 1 cm squares — you'd fit exactly 40 of them. **Why the wrong options tempt you** - **Option A (14 cm²)**: This is what you get if you *add* length and width (10 + 4 = 14). That's actually the **perimeter divided by 2**, not area! The trap is confusing "adding" with "multiplying." - **Option B (28 cm²)**: This is the full **perimeter** (2 × 10 + 2 × 4 = 28). Again, mixing up perimeter with area. - **Option D (20 cm²)**: Maybe you multiplied 10 × 2 or 4 × 5? A calculation slip. **Quick takeaway** Area = multiply the sides; Perimeter = add all sides around. For rectangles, always **multiply length by width** for area! 🎯