# Lines And Angles | NCERT Class 7 Maths Chapter 5 Solutions

**Basic Facts:**

A **line-segment** has two end points.

A **ray** has only one end point (its vertex).

A **line** has no end points on either side.

An **angle **is formed when two lines (or rays or line-segments) meet.

When the sum of the measures of two angles is 90 degree, the angles are called **complementary **angles.

When the sum of the measures of two angles is 180 degree, the angles are called **supplementary **angles.

**A linear pair** is a pair of adjacent angles whose non-common sides are opposite rays.

When two lines l and m meet, we say they intersect: the meeting point is called **the point of** **intersection.**

When lines drawn on a sheet of paper do not meet, however far produced, we call them to be **parallel **lines.

When two lines intersect, we have two pairs of opposite angles. They are called **vertically opposite** **angles**. They are equal in measure.

A transversal is a line that intersects two or more lines at distinct points.

When **a transversal** cuts two parallel lines, we have the following interesting relationships:

- i) Each pair of corresponding angles are equal.
- ii) Each pair of alternate interior angles are equal.

3. iii) Each pair of interior angles on the same side of transversal are supplementary.

class 7 maths lines and angles exercise 5.1-converted