Page 39 - Ganit Kaushal

Ex 8. Consider the following figure of a line, MN. State whether the following
statements are true or false in the context of the given figure. P
(a) Q, M, O, N, P are points on the line MN. O N
(b) M, O, N are points on a line segment MN. M
(c) M and N are end points of line segment MN. Q
(d) O and N are end points of line segment OP.
(e) M is one of the end points of line segment QO.

(f) M is a point on ray OP. (g) Ray OP is different from ray QP.
(h) Ray OP is the same as ray OM. (i) Ray OM is not opposite to ray OP.

(j) O is not an initial point of OP . (k) N is the initial point of NP and NM .
Sol. (a) T (b) T (c) T
(d) F ( N is not an end point.) (e) F ( it is in between.)
(f) F ( it is outside.) (g) T
(h) F ( they are different rays.) (i) F ( they are in opposite directions.)
(j) F ( it is, as ray OP starts from O.) (k) T

Ex 9. Here is a ray OA in the adjacent figure. It starts at O and passes through A
point A. It also passes through point B. B

(a) Can you also name it as OB? Why or why not?

(b) Can we write OA as AO ? Why or why not? (NCERT) O

Sol. (a) Yes, it can be named as OB, because it does not change its initial point and direction.

(b) No, we cannot write OA as AO , because it changes its initial point as well as direction.
Exercise 2.1
1. Fill in the blanks.
(a) A line extends indefinitely in _____ directions.
(b) A line through two points A and B is written as _____ .
(c) A line segment is a part of a line that is bounded by two distinct _____ .

(d) If the end points of a line segment are A and B, then line segment AB is written as _____ .
(e) A ray is a part of a line that has one end point and extends in one direction without _____ .
2. In the adjoining figure, write the names of: q
(a) All pairs of parallel lines. r p
(b) All pairs of intersecting lines. A G n
(c) Concurrent lines. B H F
(d) Collinear points. m
3. What is the difference between a line and a line segment?
4. State true or false for each of the following statements: C I E l
(a) There are infinitely many lines which pass through one given point. D

(b) Parallel lines never intersect.
(c) Many lines can pass through two given points.

Lines and Angles 37