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Grade 7 Math Lab: The Algebraic Pivot FREE

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Area and Circumference of Circles

50 min Grade 7 Math Lab: The Algebraic Pivot

Learning Objectives

  • Calculate circumference
  • Calculate area
  • Solve composite shape problems

Key Concepts

Circumference

C = 2πr = πd

Area

A = πr²

Theory

**Circle Formulas (r = radius, d = diameter):** - Circumference: C = 2πr = πd - Area: A = πr² **Remember:** d = 2r **π ≈ 3.14159…** **Semicircle area:** A = πr²/2

Examples

Find area with r = 5

Solution: A = π(5²) = 25π ≈ 78.54