# NCERT Solutions for Class 6 Maths Chapter 4 Exercise 4.2

NCERT Solutions for Class 6 Maths Chapter 4 Exercise 4.2 (Ex. 4.2) Basic Geometrical Ideas in PDF file format free to download or use online without downloading. All the solutions for class 6 mathematics are now updated for academic session 2020-2021 with explanation and solutions videos.

Get here step by step solution of all the questions.## Class 6 Maths Chapter 4 Exercise 4.2 Solution

Class: 6 | Mathematics |

Chapter: 4 | Basic Geometrical Ideas |

Exercise: 4.2 | Solution in Hindi and English Medium |

### CBSE NCERT Class 6 Maths Chapter 4 Exercise 4.2 Solution in Hindi and English Medium

### Class 6 Maths Chapter 4 Exercise 4.2 Solution in Videos

#### Incidence Properties in A Plane

The relations between points and lines are called the incidence properties.

###### Some of the incidence properties of points and lines in a plane:

Property- 1: An unlimited number of lines can be drawn passing through a given point. Try these experiments to verify this property.

Property- 2: Exactly one line can be drawn passing through two different given points in a plane. This line lies wholly in the plane.

Thus, we conclude that through any two points in the plane, exactly one line can be drawn. Alternatively, we can say that two points determine a unique line. Unique in the sense that this is the only such line. Moreover, this line lies wholly in the plane.

#### Intersecting Lines

In Fig., two lines l and m are shown. Both the lines pass through point O. We say l and m intersect at O. If two lines have one common point, they are called intersecting lines.

##### Parallel Lines

Two lines in a plane are parallel if they do not intersect each other however far they are produced in either direction.

If two lines m and n are parallel, we write m || n.

The opposite sides of a square, the opposite edges of a ruler and the tracks of railway lines are some examples of parallel lines.

Property- 3: Two lines in a plane either intersect at exactly one point or are parallel.

Note: It should be noted that the above property is true only for line drawn in a plane. In space there can be lines which are neither parallel nor intersecting.

#### Concurrent Lines

Three or more lines in a plane are said to be concurrent if they all pass through the same point. This point is called the point of concurrence.

The lines l, m, n, o… are concurrent as they all pass through the same point K. So, K is the point of concurrence of the lines l, m, n, o.

##### Collinear Points

Three or more points in a plane are said to be collinear if they all lie on the same line. This line is called the line of collinearity.

##### Give two examples from your environment of: (i) plane (ii) parallel lines (iii) intersecting line

(i) A playground, Black board, floor and walls of a building.

(ii) we can see railway line, opposite walls of a building.

(iii) Scissors are great examples of intersecting lines.

##### What do mean by concurrent lines?

Three or more lines in a plane are said to be concurrent, if they all pass through the same point. This point is called the point of concurrence.

##### How many lines can be drawn from a point?

From a point we can draw infinite number of lines. These lines are also called concurrent lines and point is called point of concurrency.