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Middle SchoolGeometry
Area & Perimeter
Measuring the boundary and space of shapes
Calculate the perimeter (boundary) and area (space) of common 2D shapes.
✓ Perimeter = sum of all sides (units: cm,...✓ Area = space inside shape (units: cm², m...✓ Rectangle: A = lw, P = 2(l+w)
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📖 Understanding Area & Perimeter
Perimeter is the total length of the boundary around a shape. To find the perimeter, add all the side lengths together.
Area is the amount of space inside a 2D shape. It is measured in square units (cm², m², km²).
Key formulas: Rectangle — Area = length × width, Perimeter = 2(l + w). Triangle — Area = ½ × base × height. Circle — Area = πr², Circumference = 2πr.
When solving area problems, always check the units. If dimensions are in cm, area is in cm².
🔑 Key Points to Remember
- ✓Perimeter = sum of all sides (units: cm, m)
- ✓Area = space inside shape (units: cm², m²)
- ✓Rectangle: A = lw, P = 2(l+w)
- ✓Triangle: A = ½bh
- ✓Circle: A = πr², C = 2πr (π ≈ 3.14159)
#area#perimeter#circle#rectangle#triangle#middle school
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