Question

if each edge of a cube be three times how much will the total surface area become?​

Answer 1

Answer:

Let the edge of cube be 'a'

surface area = 6a^26a2

If the edge is doubled edge = 2a

surface area = 6\left(2a\right)^26(2a)2

= 6\times4a^26×4a2

=24a^224a2

If increases by 4 times, i.e \frac{24a^2}{6a^2}6a224a2

= 4

(ii)

Let the edge be 'a'

Volume = a^3a3

When edge is doubled, it is 2a

Volume = \left(2a\right)^3(2a)3

=\ 2\times2\times2\ a^3= 2×2×2 a3

= 8a^38a3

Volue increases by 8 times

i.e. \frac{8a^3}{a^3}\ =\ 8a38a3 = 8

Answer 2

Refer this attachment mate :D