Chapter 10. Mensuration | CBSE Class 6th (VI) Mathematics | Exercise 10.2 - Solutions

Things to remember...

• The amount of surface enclosed by a closed figure is called its area.
• Surface Area of a figure  can be broken into exact numbers or approximate numbers of square units
• Depending upon the figure, some of square units may be completely covered, or partially covered.
• While using a squared paper, to calculate the area of a figure , we may use the  conventions :
  
  
  
  • The area of one full square is taken as 1 sq unit. .
  •  The portions of area that are less than half a square are Ignored .
  • The portions of area that are more than half a square are counted as one square.
  • The portions of area that are  are exactly half the square are counted,  as 1/2 sq unit.
  This convention gives a fair estimate for  the measurement  of   area under consideration

EXERCISE 10.2 | Mensuration | CBSE Class 6th (VI) Mathematics | Chapter 10 - Solutions

Question 1. Find the areas of the following figures by counting square:

Solution.

Figure	Covered Area	Number	Area estimate (sq units)
Figure (a)	(i) Fully-filled squares	9	9
	(ii) Half-filled squares	0	0
	(iii) More than half-filled squares	0	0
	(iv) Less than half-filled squares	0	0
	Total area of figure (a)	=	9 sq units
Figure (b)	(i) Fully-filled squares	5	5
	(ii) Half-filled squares	0	0
	(iii) More than half-filled squares	0	0
	(iv) Less than half-filled squares	0	0
	Total area of figure (b)	=	5 sq units
Figure (c)	(i) Fully-filled squares	2	2
	(ii) Half-filled squares	2	4 × 1/2 = 2
	(iii) More than half-filled squares	0	0
	(iv) Less than half-filled squares	0	0
	Total area of figure (c)	=	4 sq units
Figure (d)	(i) Fully-filled squares	8	8
	(ii) Half-filled squares	0	0
	(iii) More than half-filled squares	0	0
	(iv) Less than half-filled squares	0	0
	Total area of figure (d)	=	8 sq units
Figure (e)	(i) Fully-filled squares	10	10
	(ii) Half-filled squares	0	0
	(iii) More than half-filled squares	0	0
	(iv) Less than half-filled squares	0	0
	Total area of figure (e)	=	10 sq units
Figure (f)	(i) Fully-filled squares	2	2
	(ii) Half-filled squares	4	2 × 1/2 = 2
	(iii) More than half-filled squares	0	0
	(iv) Less than half-filled squares	0	0
	Total area of figure (f)	=	4 sq units
Figure (g)	(i) Fully-filled squares	4	4
	(ii) Half-filled squares	4	4 × 1/2 = 2
	(iii) More than half-filled squares	0	0
	(iv) Less than half-filled squares	0	0
	Total area of figure (g)	=	6 sq units
Figure (h)	(i) Fully-filled squares	5	5
	(ii) Half-filled squares	0	0
	(iii) More than half-filled squares	0	0
	(iv) Less than half-filled squares	0	0
	Total area of figure (h)	=	5 sq units
Figure (i)	(i) Fully-filled squares	9	2
	(ii) Half-filled squares	0	0
	(iii) More than half-filled squares	0	7
	(iv) Less than half-filled squares	3	0
	Total area of figure (i)	=	9 sq units
Figure (j)	(i) Fully-filled squares	2	2
	(ii) Half-filled squares	4	4 × 1/2 = 2
	(iii) More than half-filled squares	0	0
	(iv) Less than half-filled squares	0	0
	Total area of figure (j)	=	4 sq units
Figure (k)	(i) Fully-filled squares	4	4
	(ii) Half-filled squares	2	2 × 1/2 = 1
	(iii) More than half-filled squares	0	0
	(iv) Less than half-filled squares	0	0
	Total area of figure (k)	=	5 sq units
Figure (l)	(i) Fully-filled squares	2	2
	(ii) Half-filled squares	0	0
	(iii) More than half-filled squares	6	6
	(iv) Less than half-filled squares	3	3
	Total area of figure (l)	=	8 sq units
Figure (m)	(i) Fully-filled squares	7	7
	(ii) Half-filled squares	0	0
	(iii) More than half-filled squares	7	7
	(iv) Less than half-filled squares	0	0
	Total area of figure (m)	=	14 sq units
Figure (n)	(i) Fully-filled squares	11	11
	(ii) Half-filled squares	0	0
	(iii) More than half-filled squares	7	7
	(iv) Less than half-filled squares	0	0
	Total area of figure (n)	=	18 sq units

CBSE Class 6th (VI) Mathematics | Chapter 10. Mensuration : EXERCISE 10.2 - Solutions