Vertical angles – they’re equal! In this proposition Euclid proves that both pairs of vertical angles formed by two intersecting lines are equal. (In the black line diagram here, angles AEC and DEB as well as angles CEB and AED.) The larger Greek text at the top of the artwork is the phrase for “vertical angles” and the smaller Greek text on the left is a bit of the proof in Greek.
Vertical angles made me think of street maps. So, I wanted to find a city street map with streets that formed some very clear vertical angles. Found what I was looking for on a vintage street map of Washington, DC. A collage of this map underlies the entire piece, visible in only a few spots. Sticking with the city map theme, when I needed a way to blend the areas of blue paint and rusty orange paint, a gridded stamp seemed the way to go.