Current Electricity Part 2

Given all resistances have same resistance R.
Now, we can redraw the circuit as belowLet resistances be R1,R2,R3 and R4.
∵‌

R1

R3

=‌

R2

R4

So, circuit will behave as a Wheatstone bridge and no current will flow through midthle resistor.
∴‌‌Req‌‌=‌

(R1+R2)(R3+R4)

(R1+R2)+(R3+R4)

‌‌=‌

(R+R)(R+R)

(R+R)+(R+R)

‌‌=R