visualising solid shapes

Visualizing Solid Shapes

Fa – 4 Math's Individual activity

Done By : AADHAVAN 8B

IntroductionWhat is shape ?

The external form or appearance characteristic of something is known as shape. There are two types of shapes : 2D 3D

Properties Of 3 Dimensional Shapes

Three-dimensional shapes have four properties that set them apart from two-dimensional shapes: faces, vertices, edges and volume. These properties not only allow you to determine whether the shape is two- or three-dimensional, but also which three-dimensional shape it is.

Face • The part of the shape

that is flat or curved.

• Eg : Cube has six faces

Edge • The part of the shape

where two faces meet

• Eg : Cube has twelve edges

Vertex • The part of the shape

where three or four edges meet

• Eg : Pyramid has four edges

What is net of a shape ?

A net is the shape that is formed by unfolding a three-dimensional figure. In other words, a net is composed of all of the faces of the figure.

Platonic Solid Picture Number

of Faces Shape of

Faces

Number of Faces at Each Vertex

Number of

Vertices

Number of Edges

Unfolded Polyhedron (Net)

Tetrahedron

4 Equilateral Triangle (3-sided)

3 4 6

Cube

6 Square (4-sided) 3 8 12

Octahedron

8 Equilateral Triangle (3-sided)

4 6 12

Dodecahedron

12 Regular

Pentagon (5-sided)

3 20 30

Icosahedron

20 Equilateral Triangle (3-sided)

5 12 30

PolyhedronsA polyhedron is a solid shape bounded by polygons whereas non-polyhedrons do not have polygon shaped faces. Cubes, cuboids, prisms, and pyramids are few examples of polyhedrons. Spheres, cones and cylinders are a few examples of non-polyhedrons.

Polyhedrons Non-polyhedrons

What is a Map ?• A map is a graphic representation of a portion of

the earth's surface drawn to scale, as seen from above.

• It uses colors, symbols, scales and labels to represent features found on the ground.

Colours used in Map• Black: Indicates cultural (man-made) features such as buildings and roads, surveyed spot

elevations, and all labels.• Red-Brown: The colours red and brown are combined to identify cultural features, all

relief features, non-surveyed spot elevations, and elevation, such as contour lines on red-light readable maps.

• Blue: Identifies hydrography or water features such as lakes, swamps, rivers, and drainage.• Green: Identifies vegetation with military significance, such as woods, orchards, and

vineyards.• Brown: Identifies all relief features and elevation, such as contours on older edition maps,

and cultivated land on red-light readable maps.• Red: Classifies cultural features, such as populated areas, main roads, fire station, and

boundaries, on older maps.• Other: Occasionally other colours may be used to show special information. These are

indicated in the marginal information as a rule.

Scales used in Maps• A map is a scaled graphic representation of a portion of the earth's

surface.

• The scale of the map permits the user to convert distance on the map to distance on the ground or vice versa.

• The ability to determine distance on a map, as well as on the earth's surface, is an important factor in planning and executing military missions.

• Distances Shown on the map are proportional to the actual distance on the ground.

• While drawing a map, we should take care about:How much of actual distance is denoted by :

1mm or 1cm in the map• It can be : 1cm = 1 Kilometres or 10 Km or 100Km

etc.• This scale can vary from map to map but not with

in the map.