IN geometrical discussions, such as arise out of a great variety of physical problems, it is frequently necessary to refer to an acute or obtuse angle A as being equal to another acute or obtuse angle ...

Did you know that one half turn is 180°? If the straight line or half turn is divided into two angles, and we know one of the angles, we can work out the other. Here 120° + 60° = 180° If we just had ...

Parallel lines are straight lines which have the same direction and so never meet. Arrowheads show lines are parallel. A straight line that cuts a pair of parallel lines is called an intersecting ...

Class 9 Maths Chapter 6 Lines and Angles is available here for download in PDF format. We have provided here the latest edition of the chapter which is published by the NCERT on its official website.