Basic Geometrical Ideas
Exercise 4.1
Ex 4.1 Question 1.
1. Use the figure to name:
(a) Five points
(b) A line
(c) Four rays
(d) Five line segments
(a) Five points = B ,C ,D ,E and O
(b) A line
(c) Four rays
,
,
and
.
(d) Five line segments
,
,
,
and
Ex 4.1 Question 2.
Name the line given in all possible (twelve) ways, choosing only two letters at a time from the four given.
Solutions:
The lines are
,
,
,
,
,
,
,
,
,
,
,
Ex 4.1 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.
Solutions:
(a) Line containing point E
(b) Line passing through A
(c) Line on which O lies
(d) Two pairs of intersecting lines
,
and
,
Ex 4.1 Question 4.
How many lines can pass through (a) one given point? (b) two given points?
Solutions:
(a) An infinite number of lines can pass through one given point.
(b) Only one line can pass through two given points.
Ex 4.1 Question 5.
Draw a rough figure and label suitably in each of the following cases:
(a) Point P lies on
.
(b) 
and 
intersect at M.
(c) Line l contains E and F but not D.
(d) 
and 
meet at O.
Solutions:
Ex 4.1 Question 6.
6. Consider the following figure of line 
. Say whether following statements are true or false in context of the given figure.
(a) Q, M, O, N, P are points on the line 
.
(b) M, O, N are points on a line segment
.
(c) M and N are end points of line segment
.
(d) O and N are end points of line segment 
.
(e) M is one of the end points of line segment 
.
(f) M is point on ray 
.
(g) Ray 
is different from ray
.
(h) Ray 
is same as ray
.
(i) Ray 
is not opposite to ray 
.
(j) O is not an initial point of 
(k) N is the initial point of 
and 
.
Solutions:
(a) True
(b) True
(c) True
(d) False
(e) False
(f) False
(g) True
(h) False
(i) False
(j) False
(k) True