VISUALISING SOLID SHAPES!!!

by saleema 8-A

CONTENTS…1. Plane shapes a and solid shapes.2. 2~dimensional figure.3. 3~dimensional figure.4. Net..5. Platonic solid ~ tetrahedron cube octahedron icosahedrons dodecahedron6. The Euler's formula

Plane shapes a and solid shapes.

Plane shapes have two measurements like length & breadth, Therefore it is also called 2-D figures

Eg~ square & circle

Solid shapes have 3 measurement length, breadth and height/depth.

Eg~ Cylinder & cuboid

2~dimensional figure.

Figures having length and breadth are known as two dimensional figures or 2-D figures.

Eg. A Polygon & A Circle

3~dimensional figure.

Figures having length, breadth & height/Depth is called 3-dimensional figures or 3-D figures.

Eg~ Sphere & Cone

Net..

A net for a 3-D shape is a sort of Skelton-outline in 2-dimension which, when folded, results in three dimensional shapes.

Eg~ net of a cuboid&triangular prism

Platonic solid A Platonic solid is a polyhedron. Any

polyhedron at least three polygons must meet at a vertex to form a solid angle. The sum of all plane angels forming the solid angel at a vertex must be less than 360*.

There are five polyhedron. They are~ *tetrahedron, cube, octahedron. An

icosahedrons & dodecahedron

A TETRAHEDRON

Face ~ 4 triangular facesVertices ~ 4 vertices Edges ~ 6 edges

Euler's formula= F+V-E=2 4+4-6=2

CUBE

Face ~ 6 square facesVertices ~8 verticesEdges ~ 12 edgesEuler’s formula=F+V-E=2 6+8-12=2

OCTAHEDRON

Faces ~ 8 triangular facesVertices ~ 6 verticesEdge ~ 12 edgesEuler’s formula= F+V-E=2

8+6-12=2

AN ICOSAHEDRON

Faces ~20 triangular facesVertices ~ 12 verticesEdges ~ 30 edgesEuler’s formula= F+V-E=2 20+12-30=2

DODECAHEDRON

Faces ~12 pentagonal faces

Vertices ~ 20 verticesEdge ~ 30 edgesEuler’s formula= F=V-E=2 12+20-30=2

Euler’s FormulaThe number of faces (F), The number of

vertices(V) and the number of edges (E) of a simple

convex polyhedron are connected by the Euler’s formula.

The Euler’s formula can be done by 2 ways F+V=E+2 (eg- 6+8=12+2)

( 14=14 ) F+V-E=2 (eg- 6+8-12=2)