Assuming that the bases are all within right angles of each other:
Form a triangle with vertices at home base, first, and second. Home to first is 90ft and first to second is also 90ft.
Use the formula a^2+b^2=c^2 to find the the missing length.
90^2+90^2=c^2
8100+8100=c^2
16200=c^2
Sqrt(16200)=c
c=127.279