Euclid Elements Book 1 Prop 43 (correct)
Proposition: https://mathcs.clarku.edu/~djoyce/java/elements/bookI/propI43.html
This says the purple parallelogram and the green parallelogram have the same area.
This one was a marathon to make, but omg it was satisfying. Parallel copy hell.
https://odysee.com/@DoctorAjayKumar/ee-book1-prop43