Page 110 - ICSE Math 4

A line can be horizontal, ver cal, slan ng or curved.

A
R E K
M N
S
L
B F

Remember

A straight line can only be drawn to join any two given points. M
However, many curved lines can also be drawn to join the two given
points in diff erent ways.
For example, look at the fi gure shown alongside. The shortest
distance between points M and N is shown by the straight line MN
N
rather than the other two curved lines.

Line Segment A B
P R
When two points are joined or connected with a straight line
using a ruler, we get a fi gure called line segment.
S
For example, when we join point A and point B with a straight
line using a ruler, we get a line segment AB. It is wri en as AB.
Q
A and B are the end points of AB. A line segment has a fi xed
length which can be measured by a ruler. It cannot be extended Top Tip
from any side. It can be horizontal, ver cal or slan ng.
A line segment is a
Ray part of a line.

A ray is a straight line which has a fi xed star ng point but
no end point. It has no fi xed length. It can be extended Top Tip

endlessly to any length in one direc on and hence, cannot
be measured. The fi xed point of a ray is shown by a point A ray is always
named from its
and the extended part is shown by an arrow head that can starting point.
be extended endlessly.

For example, when we extend a line segment, say AB, from one end and put an arrowhead
to it, we get a ray AB. It is wri en with an arrow on top as AB, where A is its end point.

A B Q P

Rays of the sun is a very good example of rays. They start from the sun and can be extended
to any length.

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