1. 2D Plane Geometry Formulas
Circle
Area = π·r² | Circumference = 2·π·r = π·d
Example: Circle with radius 7 cm has Area ≈ 153.94 cm² and Circumference ≈ 43.98 cm.
Rectangle
Area = length × width | Perimeter = 2·(length + width)
Triangle
Area = 1/2 × base × height | Perimeter = a + b + c
2. 3D Solid Geometry Formulas
Cylinder
Volume = π·r²·h | Total Surface Area = 2·π·r·(r + h)
Sphere
Volume = (4/3)·π·r³ | Surface Area = 4·π·r²
3. Interactive Visual Geometry on CalcWillow
Open CalcWillow's Geometry Calculator tab to select any 2D shape or 3D solid. Live vector SVG graphics render dynamically on screen as you adjust dimensions.