9. Three equal cubes are placed adjacently in a row. Find the ratio of total surface area of the new cuboid to that of the sum of the surface areas of the three cubes.
Answers
Answered by
5
TSA of cube = 6a 2
Length of new rectangular prism = 3a , width = a and height = a
TSA of rectangular prism = 2( lw + wh + lh)
⇒ = 2 (3a x a + a x a + 3a x a)
⇒ = 2 ( 3a 2 + a 2 + 3a 2 )
⇒ = 2 ( 7a 2 )
TSA of rectangular prism = 14a 2
∴ TSA of rectangular prism / TSA of a cube 3 cubes = (14a 2 ) / 18a 2
∴ Ratio = 14 / 18 = 7 / 9
∴ The ratio is 7 : 9
Similar questions