Question

Define the following terms:
(a) Parallel lines
(b) Intersecting lines
(c) Concurrent lines

Answer 1

(a) Parallel Lines: Two lines are said to be parallel if

(i) they never meet or never intersect each other even if they are extended to infinity
(ii) they are coplanar

(b)Intersecting lines: Lines that have one and only one point in common are known as intersecting lines. For intersection, the following conditions have to be met:
(i) A minimum of two lines are required for intersection.
(ii) The common point where all the intersecting lines meet is called the point of intersection.
(iii) All the intersecting lines form angles at the point of intersection.

In the figure, there are two lines AB and CD, which intersect at O.

(c) Concurrent lines: A set of lines or curves are said to be concurrent if they intersect at the same point.



In the above figure, the three lines are concurrent because they intersect at point P, which is
the point of concurrence.