Example 9: Using Kirchhoff's rules. Calculate the currents 11, 12, and 13 in the three branches of the circuit in the figure. 30 Ω h ww 11 r = &₁₂ = 40 Ω 13 10 45 V a WW d b r = 20 Ω 12 80 V ΙΩ ww g f