To find the total resistance in a complex circuit, identify resistors in series and parallel, then combine them step-by-step using the appropriate formulas. For series resistors, add their resistances (Rtotal = R1 + R2 + ...). For parallel resistors, use the formula 1/Rtotal = 1/R1 + 1/R2 + ... Simplify the circuit by reducing series and parallel combinations until you arrive at a single equivalent resistance