Class 12 Maths Three Dimensional Geometry | Introduction |

**Introduction**

We will learn about the 3-D geometryand also about the 3-D coordinate system.

How to make use of vector algebra in 3-D geometry.

We will discuss about the direction cosines and direction ratios of a line joining two points and also about the equations of plane and lines in space under different conditions.

In case of 3-D the three coordinateplanes divide the space into eight parts known as octants.

Some examples of where 3-D geometry is being used:

- The path followed an aeroplane is along the x, y and z coordinates.

- The path followed by a ball in a room is another example of 3-D.When a ball is thrown it will hit the walls and bounce back. The path followed by the ball was in all the 3 directions (x, y,and z).

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