**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.

**(2) Write how many lines can be drawn through:**

(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

(ii) Lines printed on your note-book and edge of your table-top

(iii) Top of your study table a wall of your class-room

(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:**

**(10) Mark two points P and Q on a piece of paper. How many lines can you draw:**

(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:**

**(14) Use a ruler and find whether following points are collinear or not:**

(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