Cylinder from A4 (2)

 

resource: nzmaths

Cylinder from A4

 

How many cubes?

How many small cubes are needed to complete the given figure into a cube?

Unit Cube

Unit cube#MTBoS #iteachmath #math #maths pic.twitter.com/jE5m8SzcAV

— Idan Tal (@MagicPi2) June 15, 2020

Problem 138: Sphere, Cylinder and Cone

Can we say volume of cone + volume of cylinder=volume of cylinder is true for all cases? Why?

Problem 135: Cylinder inside Sphere

Problem 65: Rectangular Prism with Same Volume and Surface Area

Can you construct a rectangular prism such that its volume and surface area will have same numerical value?

Platonic Solids

Plato and his disciples were so fascinated by the idea that there were only 5 regular polyhedra that each associated to a natural element: the tetrahedron with the fire, the Hexahedron to the Earth, the octahedron to the air, the dodecahedron to the cosmos and the icosahedron to water. (source)

Plato believed that geometry hid sacred truths describing reality. They say that when he founded the School of Athens in 387 BC he placed a sign at the entrance that said: "Let no one ignorant of the geometry between here."

3D Paper Models

Sources for the nets:
1. Paper Models of Polyhedra
2. Nets-Polyhedra