[deleted] so first, u count up the the one sides rhombusses from bottom to top, initally, there is 2 at second layer, 4 at next, 6 at next, so u can see where this is going, this goes until last layer, so 2+4=6+6=12 and this keeps going until u reach the top which is 16 rhombuses so adding that gets 72, now 2 sided ones, it is esentially the same pattern but starts at a higher layer and u so it would be 42 as it starts two layers ahead of the first rhombus, so minus 2 every side u increase by 1, so third one would be 20, 4 th would be 6 and that is the max, so add that up and u get 140
