Question

if each edgeof a cube is increased by 25%,find the percentage increase in its suface area​

Answer 1

Answer:

6*6*6=216

7.8*7.8*7.8= 474.55

258.55/216= 1.197= 119.7% increased

Step-by-step explanation:

119.7% increased

Answer 2

Step-by-step explanation:

To find the % increase in surface area, consider:

A cube has 6 square surfaces. The surface area of each surface is the edge length [S] squared (remember L*W?).

So, the surface area of a cube is 6*S^2 = 6*S*S.

If the length of each edge is increased by 25%, the new surface area is 6*(1.25*S)*(1.25*S)

Or, 6*( (5/4)*S )*( (5/4)*S ) = 6* (25/16) * S^2

= (75/8) * S^2 this is a surface area of 9.375 * S^2

And as a ratio, the increase is

( 9.375*S*S ) / ( 6*S*S) = 1.5625 times as large

As a %, the surface area would increase by 56.25%