There are plenty of concepts and segments in mathematics that keep students stressed and drained. Well, if you are one of such students then you must not skip to take proper assistance in their understanding. You cannot perform well in maths unless you have understanding.

Do you feel that you are the only one who is failing to get the concept of **Class 9 Maths Ch-6 Lines and Angles**? Well, no, you are not the only one. There are many students who feel nervous about this concept. Don’t feel disappointed because you cannot understand the concepts with a broken mood. Just have a look at different aspects of a concept and you will get an idea about it.

**What is a Line?**

Talking about line, it is a collection of points along a single straight path. One line extends in both the directions and possesses no endpoints. It has no definite length too.

**Line segment**

Talking about a line segment, it is a portion of a line with the two end points. There is only one line segment that joins two given points.

**Ray**

A portion of line having one end point is known as a ray.

**The Collinear points**

All the points that remain on the same line are known as the collinear points.

**Angle**

The two rays initiating from a same end point generate an angle. Consider two rays AB and AC originating from same point A form an angle called as ∠BAC or ∠CAB or ∠A. The rays that create the angle are known as the arms of the angle. The end point is known as the vertex of the angle. Always remember that the size of an angle is measured in degrees only.

**A peep into the types of angles**

**Acute angle**

Angles that are measuring less than 90° but more than 0° are known as acute angles.

**Right angle**

Any angle that is measuring 90° is called a right angle. A right angle is generated by the juncture of two upright lines.

**Obtuse angle**

Angles that are measuring greater than 90° but less than the 180° are known as obtuse angles.

**Straight angle**

An angle that is measuring 180° is known as a straight angle.

**Reflex angle**

The angles that are measuring greater than 180° but less than 360° are known as reflex angles.

**Adjacent angles**

Two angles are known as adjacent in case they possess a common arm and a common vertex.

**Linear pair of angles**

Two adjacent angles form a linear pair in case their sum is 180°. Non-common arms of linear pair of angles create a straight line.

** Angles that is opposite vertically**

When two lines cross, four angles are created. The angles that are opposite to each other are known as vertically opposite angles. There are two sets of vertically opposite angles.

**The Complementary angles**

Two angles are called complementary in case their sum is 90°.

There are many other lines and angles too that you can understand once you dive into the concept!

**Conclusion**

Thus, it gets important to take assistance of professionals or simply go through some of the material to understand concepts. So, whether you are in search of **NCERT Solutions for Class 9th Chapter 6** or you are confused about anything else, feel free to talk to professionals!