Triangle having ratio of sides 3:4:5

lets say the three sides are 3x , 4x, 5x

s = (3x + 4x + 5x) / 2 = 6x
Area = sqrt(6x (6x-3x)(6x-4x)(6x-5x) )
Area = sqrt(6x (3x)(2x)(1x))
Area = sqrt(36x)
Area = 6x sq. units.

Height of the prism is 12cm

so the surface area {(2*6x)+(3x+4x+5x)*12}

156x=576 cm2

=> x=3

and the formula of volum is= triangle area x prism height

i think you can do the rest....

is it okay?
if I could do this, i would not have bothered you. I'd appreciate if you could complete it.
okay wait