Area and volume of solids
A cereal box, a tin can, an ice cream cone and a ball each have a formula for how much card covers them and how much they hold. Unfold each solid in 3D, change its size with sliders and watch the numbers follow.
Progress
- 1Nets and surface areaA cube with 4 cm edges is wrapped by exactly 96 cm² of card, and you can see all of it at once when the cube is opened flat.
- 2Volume of prismsA fish tank 50 cm long, 30 cm wide and 40 cm deep holds 60,000 cm³ of water, which is exactly 60 litres.
- 3CylindersPeel the label off a tin can and it lies flat as a rectangle whose width is the can's circumference, 2πr.
- 4Pyramids and conesA cone of water poured into a cylinder with the same base and height fills it exactly one third of the way.
- 5SpheresArchimedes asked for a sphere inside a cylinder to be carved on his tomb, because the sphere has exactly two thirds of the cylinder's volume.
- 6Faces, edges and vertices: Euler's formulaCount the faces, subtract the edges and add the vertices of any ordinary polyhedron and the answer is always 2.
- 7Scaling: double the lengthsMake every length of a box twice as long and it needs 4 times the card but holds 8 times as much.
Sources for this course (8)
- (checked 2026-10-17; reordered 2026-10-19: curriculum and textbooks first, then reference works and units, history last)
- Curriculum: 교육부 고시 제2022-33호 [별책 8] 수학과 교육과정 (ncic.re.kr/inv/org/download.do?year=2022&seq=10003559&orgType=ogi4, PDF read 2026-10-19: 초등학교 5~6학년군 [6수03-03]~[6수03-08] 직육면체·정육면체·각기둥·각뿔·원기둥·원뿔·구, 원기둥의 전개도, "각뿔과 원뿔의 전개도는 다루지 않는다", 원주율의 근삿값 3.14, [6수03-17]~[6수03-19] 직육면체와 정육면체의 겉넓이, 1cm³·1m³, 부피; 3~4학년군 [4수03-17] 들이 1L·1mL; 중학교 1~3학년군 [9수03-06] 부채꼴, [9수03-07] 다면체와 회전체, [9수03-08] 입체도형의 겉넓이와 부피, 도형의 닮음·닮음비; 오일러 공식은 성취기준에 이름으로 없음)
- Textbook: OpenStax Prealgebra 2e, 9.6 Solve Geometry Applications: Volume and Surface Area (openstax.org/books/prealgebra-2e/pages/9-6-solve-geometry-applications-volume-and-surface-area)
- Reference: Wolfram MathWorld, Polyhedral Formula (mathworld.wolfram.com/PolyhedralFormula.html)
- AMS Feature Column, Euler's Polyhedral Formula (ams.org/publicoutreach/feature-column/fcarc-eulers-formula)
- BIPM SI Brochure and NIST SI Units - Volume (litre and cubic metre)
- History block only: MacTutor, Archimedes biography (On the Sphere and Cylinder, sphere = 2/3 of the circumscribed cylinder, the figure on his tomb, Cicero's search; mathshistory.st-andrews.ac.uk/Biographies/Archimedes/)
- MacTutor, A history of Topology (Euler's 1750 letter to Goldbach with v − e + f = 2; mathshistory.st-andrews.ac.uk/HistTopics/Topology_in_mathematics)
Checked: 2026-10-17