Application of Kirchhoff's Current Law (KCL) or Kirchhoff's Voltage Law (KCL) can require addition or subtraction of phasors.

- Left click the mouse once in the frequency domain to specify a phasor. The corresponding sinusoid will be displayed. Both the phasor and sinusoid will be shown in blue.
- Left click the mouse in the frequency domain a second time to specify a second phasor. The sinusoid corresponding to the second phasor will be displayed. The phasor and sinusoid will again be shown in blue.
**If**the phasor corresponding to the sum of the two blue phasors fits in the part of the frequency domain that is shown, this phasor and the corresponding sinusoid will be displayed. The phasor representing the sum of the two blue phasors and sinusoid representing the sum of the two blue sinusoids will be shown in green.Grey lines are used to show the parallelogram used for graphical addition of phasors.

- Left click the mouse in the frequency domain a third time to clear both the frequency and time domains to set ready for another example.

Repeat this sequence as often as desired.

The source.