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सी.आई.एस.सी.ई.आईसीएसई ICSE Class 8

Find the Volume and Total Surface Area of a Cube Whose Each Edge is : (I) 8 Cm (Ii) 2 M 40 Cm. - Mathematics

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प्रश्न

Find the volume and total surface area of a cube whose each edge is:
(i) 8 cm
(ii) 2 m 40 cm.

योग
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उत्तर १

(i)

Edge of the given cube = 8 cm

Volume of the given cube = (Edge)3 = (8)3 = 8 x 8 x 8 = 512 cm3

Total surface area of a cube = 6(Edge)2 = 6 x (8)2 = 384 cm2

(ii)

Edge of the given cube = 2 m 40 cm = 2.40 m

Volume of a cube = (Edge)3

Volume of the given cube = (2.40)3 = 2.40 x 2.40 x 2.40 = 13.824 m2

Total surface area of the given cube = 6 x 2.4 x 2.4 = 34.56 m2

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उत्तर २

Formulae for a Cube:

Volume (V): V = a3

Total Surface Area (TSA): TSA = 6a2

(i) Edge length = 8 cm

Volume: V = a3 = 83 = 512 cm3

Total Surface Area: TSA = 6a2 = 6 × 82 = 6 × 64 = 384 cm2

(ii) Edge length = 2 m 40 cm

Convert 2 m 40 cm to centimeters:

2 m = 200 cm, so, 2 m 40 cm = 200 + 40 = 240 cm.

Volume: V = a3 = 2403 = 240 × 240 × 240 = 13,824,000 cm3

Convert to cubic meters:

1 m3 = 1,000,000 cm3 `=>V = (1,38,24,000)/(10,00,000) = 13.224  m^3`

Total Surface Area: 

TSA = 6a2 = 6 × 2402 = 6 × 57,600 = 345,600 cm2

Convert to square meters:

`1  m^2 = 10000  cm^2 => TSA = 345600/10000 = 34.56  m^2`

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  क्या इस प्रश्न या उत्तर में कोई त्रुटि है?
अध्याय 21: Surface Area, Volume and Capacity - Exercise 21 (A) [पृष्ठ २३८]

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सेलिना Concise Mathematics [English] Class 8 ICSE
अध्याय 21 Surface Area, Volume and Capacity
Exercise 21 (A) | Q 5 | पृष्ठ २३८

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