the edges of rectangular solid have lengths 2x,3x and 5x. what is the total surface area of the solid
We have 6 "faces"......with three different rectangular areas being "doubled"...so we have.......
2 [ (2x * 3x) + (2x * 5x) + (3x * 5x)] =
2 [ 6x2 + 10x2 + 15x2 ] =
2 [ 31x2 ] =
62x2
