Are quad and tetra cognate terms?

Yes, "quad" and "tetra" are cognate terms, both deriving from Latin and Greek roots, respectively. "Quad" comes from the Latin "quattuor," meaning four, while "tetra" comes from the Greek "tetra," also meaning four. They are often used in various contexts, such as mathematics and geometry, to denote fourfold quantities or structures. Despite their different linguistic origins, they convey the same numerical concept.