The surface area of the cube is 864mm.
I found this by find the surface area of one of the squares first. To find this, you take the measurement of one side and multiply it by itself. So the surface area of one of the squares in the net is 144mm. Then all you do from there is multiply that number by how many squares there are in the net. So your answer is 144 x 6 which equals 864.
Hope this helps! :)
