# Selina Concise Class 6 Math Chapter 21 Fundamental Concepts Exercise 21A Solution

## EXERCISE 21A

#### (1) State, true or false, correct the statement:

(i) False; Dot has no length and width.

(ii) True

(iii) False; The line segment PQ is only written as PQ.

(iv) True

(v) False; Three points are said to be collinear, if they lie in a straight line.

(vi) True.

(i) Infinite.

(ii) Only one.

(iii) Only one.

(iv) None.

#### (3) The shaded region of the given figure shows a plane: (a) Name:

(i) A, B and C

(ii) A, D and C

(iii) AC and DC

(b) State whether true or false:

(i) True

(ii) True

(iii) False

(iv) False

#### (4) Correct the statement, if it is wrong:

(i) A ray can be extended infinitely on only one side of it

(ii) A ray has indefinite length

(iii) Correct

(iv) A line has no end-point

(v) Correct

#### (5) State true or false, if false, give the correct statement:

(i) False; a line has an infinite number of points on it

(ii) False; an infinite number of lines can pass through a given point

(iii) True

#### (6) State whether the following pairs of lines or rays appear to be parallel or intersecting.

(i) Intersecting

(ii) Parallel

(iii) Parallel

(iv) Intersecting

#### (7) Give two examples, from your surroundings, for each of the following:

(i) Tip of your pencil and tip of a nail

(iv) Surface of a cricket-ball and surface of your pen.

#### (8) Under what condition will two straight lines in the same plane have: #### (9) Mark two points A and B on a page of your exercise book. Mark a third point P such that: (i) Only one

(ii) Infinite

(iii) Infinite

#### (11) The adjoining figure shows a line AB. Draw figures to represent: #### (12) The adjoining figure shows a ray AB. Draw figures to show: #### (13) The adjoining figure shows a line segment AB. Draw figures to represent: (i) No

(ii) No

(iii) Yes

(iv) No

#### (15) From the adjoining figure, write:

(i) EF ∕∕ GH, EF ∕∕ IJ and GH ∕∕ IJ

(ii) AB and CD

(iii) AB and GH

Updated: February 27, 2019 — 11:50 am