SOL003 · 3D solids & mensuration · Classes 8–12
Sphere
All points in space at distance r from a centre — a perfectly round ball.
Sphere📐 Formula
Volume = (4/3)πr³; Surface area = 4πr²
✏️ Worked example
r = 3: V = 36π ≈ 113.10; SA = 36π ≈ 113.10.
🌍 Where it is used
Balls, planets, bubbles and ball bearings.
❓ Quick check
If the radius doubles, the volume becomes…