Figure 1.9. There is an ideal voltage source on the left. The bottom end of the source goes to the bottom line of the circuit. The voltage source is labeled V Th = 13.05 v. The top end of V Th connects to the left end of a resistor labeled R Th = 400 ohms. The right end of R Th connects to the upper output terminal. The lower output terminal connects to the bottom line of the circuit. End verbal description.