Shapes

• A shape is the form of an object or its external boundary, outline, or external surface.
• Shapes can be broadly classified in 3 categories:
  1. One – Dimensional Shapes: Ex. Line
  2. Two – Dimensional Shapes: Ex. Square, Rectangle etc.
  3. Three – Dimensional Shapes:Ex. Cube,Cuboid etc.

2-D Shapes:

Shapes	Properties	Figure
Square	1. Both pair of opposite sides are equal and parallel. 2. Adjacent sides are perpendicular. 3. All sides are equal.
Rectangle	1. Both pair of opposite sides are equal and parallel. 2. Adjacent sides are perpendicular.
Rhombus	1. Both pair of opposite sides are equal and parallel. 2. Diagonals are perpendicular bisector to each other. 3. All sides are equal.
Parallelogram	1. Both pair of opposite sides are equal and parallel. 2. Diagonals bisect each other.
Circle	1. It has no sides and corners. 2. Its distance from a fixed point called centre is always same.
Triangle	1. Depending upon side length, it is further classified into 3 types. 2. Sum of all interior angles is 180 degrees.
Polygon	1. Any n sided regular figure is called a polygon where n>=3. 2. Sum of interior angles is(n-2)*180 degrees.

3-D shapes:

Shapes	Properties	Figure
Sphere	1. It has only 1 face. 2. Surface area is 4πr2. 3. Volume is 4πr3/3.
Cube	1. It has 6 faces,12 edges and 8 vertices. 2. Surface area is 6a2. 3. Volume is a3.
Cuboid	1. It has 6 faces,12 edges and 8 vertices. 2. Surface area is 2(lb+bh+hl). 3. Volume is l*b*h.
Cylinder	1. It has 3 faces. 2. Total surface area is 2π*r*(r+h). 3. Volume is πr2h.

• Other prominent 3-d figures include prisms and pyramids.Paraboloid, Ellipsoid are some other figures.