Question

The dimensions of a cuboid are in the ratio of 1:2:3 and its total surface area is 88m.find the dimensions.

Answer 1

let the dimentions be x , 2x , 3x 

So total surface area=2(lb+bh+lb)
                                     ⇒  2(2x²+6x²+3x²)
                                    ⇒   22x²=88m²
                                     ⇒    x=2m

So the dimensions are : 2m,4m,6m

Answer 2

let the sides be - a,2a,3a
so, TSA=2(lb+bh+lh)
        88 =2(a x 2a + 2a x 3a + a x 3a)
        88/2=2(2a x a +6a x a +3a x a)
        44=11a x a
        44/11  =a x a
        2 x  2 =a x a
         a =2

  so , sides are - 2 , 4 , 6