(a^1/2 -b^1/2)(a^1/2 +b^1/2)
pls help fast

Which shows the correct lengths of side c in both scales? scale 1: 45 m; scale 2: 60 m scale 1: 60 m; scale 2: 45 m scale 1: 36 m; scale 2: 27 m scale 1: 27 m; scale 2: 36 m mark this and return save and exit

How to do this , and can some one explain

Fast! find the length of cu. the triangles are similar. show your work.