Mathematics Geometry Procedural 12–14 yrs

Circles: Circumference & Area

圆形：周长与面积

Description

Calculate the circumference and area of circles using the formulae C = πd (or 2πr) and A = πr², and solve problems involving perimeters and areas of composite shapes that include circular parts

Mastery Evidence

✓ Calculate the circumference and area of a circle given its radius or diameter
✓ Find the perimeter or area of a composite shape made from rectangles and semicircles
✓ Explain the relationship between π, diameter, and circumference informally

Assessment Prompt

If your child wants to know how far a bicycle wheel travels in one full rotation, can they use the diameter of the wheel and π (pi) to work out the circumference?