Not a circle!

Exo 27:9-13 SPECIFICALLY says the tabernacle has ONLY 4 sides; a north, south, east & west.. How does 4 sides translate into a circle?? Does a circle have 4 sides?? It also says the South and North sides are 100 cubits long and the east west sides are 50 cubits long.. So how do those dimensions translate into a circle?? You are trying to pull a circle out of those verses and there is not ONE shred of evidence of a circle in those verses. Instead we see the words SIDES and we are given the dimensions of those sides. two sides are = to the other two sides.. That is by definition a rectangle NOT a circle..