NCERT Solutions for Class 11 Maths Exercise 12.1 Introduction to Three Dimensional Geometry in Hindi and English Medium updated for session 2022-2023. All the questions are given here with explanation in Hindi and English.

## NCERT Solutions for Class 11 Maths Exercise 12.1

### About Class 11 Maths Exercise 12.1 Questions

In class 10th students have studied that part of geometry which is called coordinate geometry. You will recall that we had learnt to denote the coordinates of a point on a graph paper. For example – we learnt to plot (3, 2), (2, 3) and (-2, -3), (2, -3) and so on. You know by experience that the coordinate (3, 2) is not same as coordinate (2, 3).

We also learnt to find out distance between two points. In general, we can say that we have to practice the entire grade 10 questions here with the concept of 3-D formula that is including the coordinates of z-axis.

#### Questions of Exercise 12.1 in Class 11 Maths

All this along with certain other aspects is referred to as two dimensional geometry. In two dimensional geometry we consider only two aspects – and the points are located by referring to the x – axis (horizontal axis) and the y – axis (the perpendicular axis). Here in class 11 Maths exercise 12.1, we will also deal with z-axis. Now the points have three coordinates – x, y and z. The questions are simple to solve just like in previous class.

##### Daily life use of 3-D Geometry

Now, in a real life situation we come across many aspects which are three-dimensional in nature. For example – to locate the position of the lowest tip of an electric bulb hanging from the ceiling of the roof we would need to know the perpendicular distance from the floor of the room and two adjacent walls of the room. The three number which represent three distances are called coordinates with the reference to the three coordinates place. Here in Exercise 12.1 we learn about to find the distance or similar concepts.

###### Application of 3-D Geometry

You may also think of an aeroplane flying in the sky from one place to another at different heights and at different times during the flight. Needless to say, in a real life situation three-dimensional geometry is very important. Particularly in the aviation sector. It is also important for military planners and those working in space technology. In exercise 12.1 to examples are given to explain the coordinates of a point.

You are also introduced to a new concept called octant. Octant refers to 8 parts in a three coordinate plane. There are only 4 questions for practice in exercise 12.1. These are mostly small questions requiring elementary knowledge. 