Plot the inciting incident at the left-hand base of the pyramid. The inciting incident is the event that sets the story in motion. In "Medea" it is Jason's decision to cast Medea aside and marry the young and beautiful Glauce. Jason's action fuels Medea's anger and causes her to seek vengeance.
Find scenes of rising tension. Arrange these on the left side of the pyramid. Possible events may include Creon's banishment of Medea, her request for a delay, her arguments with Jason and her poisoning of Glauce. Each event underscores Medea's desire for vengeance.
Place the climax at the apex of the triangle. The climax is the moment when the main character or protagonist achieves her desire. It's the moment of greatest tension. For Medea, it's when she overcomes her anxieties and kills her children. So intent is she on revenge that she's willing to make a great sacrifice.
Plot the falling action, or action of decreasing intensity after the climax, on the right side of the pyramid. You may find the right side of the triangle shorter than the left side. Medea meets with Jason after the murders and revels in his grief, which is, to her, a source of great satisifcation. Vengeance is complete.
Place the resolution at the base of the triangle's right side. Resolution shows the transformation of the main character. Medea has become a monster.