geometry

I am going to assume the    w + l + h = 2.04

    or is it the sum of ALL of the edges (all 12 of them)?

A rectangular box has two square ends. Its length is 15 cm greater than the breadth and the total length of its edges is 2.04m. Find its volume.

8x + 4(x+15) = 204

x = 12

V = x² ( x+15 ) = 3888 cm³