Page 160 - ICSE Math 6

Concurrent and Non-concurrent Lines

Three or more lines are known as concurrent lines if all of l r q
them pass through the same point, otherwise they are known m p
as non-concurrent lines. The point of intersection of concurrent O
lines is known as the point of concurrence. In the adjoining n
figure, lines l, m and n are concurrent and O is the point of Concurrent lines Non-concurrent lines
concurrence.

EXERCISE 14.2

1. Write True or False.
(a) Infinite number of lines can be drawn passing through a point.
(b) Two lines can be drawn passing through two distinct points.
(c) Two different lines are either parallel or intersect at a single point.

(d) Concurrent lines always meet at a single point.
(e) Three or more points are collinear if they lie in the same plane.
2. If the lines l, m, p and q intersect at A, then what are they called?

3. Given two points A and B, how many lines can be drawn passing through:
(a) point A?
(b) point B?

(c) both the points A and B?
4. Given two points A and B in the adjoining figure, draw a point P such that:

(a) the three points are collinear. A B
(b) the three points do not lie on a line.
(c) P is between A and B and the three points are collinear.
l
5. Using the adjoining figure, name the following. C

(a) Three collinear points B D m
(b) Three non-collinear points A
(c) Point of concurrence n

AT A GLANCE

¾ A point is a mark of position. It has no length, breadth and thickness.
¾ A line is a collection of points along an endless straight path.
¾ A line segment is a part of a line from one fixed point to other.
¾ A ray is a part of a line which starts from a fixed point and moves endlessly in one direction.
¾ A plane is a flat surface having infinite length and breadth.
¾ Space is a set of points having infinite length, breadth and height.
¾ Two lines lying in the same plane which do not meet even when extended indefinitely are known
as parallel lines.
¾ Two lines lying in the same plane and having a common point are known as intersecting lines.

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