Basic Geometrical Ideas-Solutions Ex-4.1

CBSE Class –VI Mathematics
NCERT Solutions
Chapter 4 
Basic Geometrical Ideas (Ex. 4.1)

Question 1. Use the figure to name:
(a) Five points
(b) A line
(c) Four rays
(d) Five line segments
Answer:  (a) Five points are: O, B, C, D, E
(b) A line: DE¯,DB¯,OE¯,OB¯
(c) Four rays: OD,OE,OC,OB
(d) Four line segments: DE¯,OE¯,OC¯,OB¯,OD¯
Question 2. Name the line given in all possible (twelve) ways, choosing only two letters at a time from the four given.
Answer: AB¯,AC¯,AD¯,BC¯,BD¯,CD¯,BA¯,CA¯,DA¯,CB¯,DB¯,DC¯
Question 3. Use the figure to name:

(a) Line containing point E.
(b) Line passing through A.
(c) Line on which O lies.
(d) Two pairs of intersecting lines.
Answer: (a) A line containing E = AE¯ or FE¯
(b) A line passing through A = AE¯ or DE¯
(c) A line on which O lies = CO¯ or OC¯
(d) Two pairs of intersecting lines are : AD¯,CO¯ and AE¯FE¯
Question 4. How many lines can pass though:
(a) one given point?
(b) two given points
Answer: (a) Infinite number of lines can pass through one given point.

(b) Only one line can pass through two given points.
Question 5. Draw a rough figure and label suitably in each of the following cases:
(a) Point P lies on AB¯.
(b) XY¯ and PQ¯ intersect at M.
(c) Line l contains E and F but not D.
(d) OP¯ and OQ¯ meet at O.

Question 6. Consider the following figure of line MN¯. Say whether following statements are true or false in the context of the given figure:

(a) Q, M, O, N, P are points on the line MN¯.
(b) M, O, N are points on a line segment MN¯.
(c) M and N are end points of line segment MN¯.
(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 point on ray OP.
(g) Ray OP is different from ray OP.
(h) Ray OPsame as ray OM..
(i) Ray OM. is not opposite to ray OP.
(j) O is not an initial point of NP¯ and NM¯.
Answer: (a) True, (b) True, (c) True, (d) False, (e) False, (f) False, (g) True, (h) False, (i) False, (j) False, (k) True