13 + 18 + 19 + (5x5) + 25 + 85 + (80x2) + (86x3) + (4x81)
13 + 18 + 19 + 25 + 25 + 85 + 160 + 258 + 324 = 927
perimeter =927cm
You just need to add all the edges together and times by the number of the edge when there is several of the same edge. Hope that makes sense.
