Page 159 - ICSE Math 6

5. Using the adjoining figure, name the pair(s) of:
(a) parallel lines l m
(b) perpendicular lines

(c) intersecting lines n
6. Fill in the blanks.
(a) Every line segment consists of __________ number of points.
(b) The figures which have different beginning and end points are known as __________ figures.
(c) A plane has __________ length and breadth.

(d) A triangle is a __________ figure formed by __________ line segments.
(e) In a rectangle, opposite sides are __________.
(f) In a square, all sides are equal and each angle is of __________.
(g) The distance of any point on a circle from the centre is known as __________ of the circle.
7. Give two examples from your surroundings of the following.
(a) point (b) line segment (c) ray (d) plane

8. Given a line segment AB, draw figures for the following.
(a) ray AB (b) ray BA (c) line AB A B

9. Which of the following are intersecting lines?
l
l l m
(a) (b) (c) (d)
m
l m m

Incidence Properties

The relations between points and lines are known as incidence properties.
Property 1: One and only one line passes through two distinct
points in a plane.
Draw two points A and B. An infinite number of lines can be A B
drawn through A and B, but there is only one line which passes
through both the points A and B.
Property 2: Two different lines in a plane are either parallel l
or intersect at exactly one point. m l
Draw two lines l and m such that they do not intersect.
Observe that they are parallel. Now, draw l and m such that m
they intersect. Observe that they intersect at one point. Now, Parallel lines Intersecting lines
draw l and m such that they intersect at more than one point. l
Observe that they are the same line. m

Collinear and Non-collinear Points

Three or more points are known as collinear points if all of C B
them lie on the same line, otherwise they are known as non- A B A C
collinear points. The line on which collinear points lie is Collinear points Non-collinear points
known as the line of collinearity.

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