The ancient Pueblo people of the Southwestern United States had no written language or numerical system, but the complexities of their architectural feats suggest they understood advanced geometry.

In a new study, published this week in the Journal of Archaeological Science: Reports, scientists at Arizona State University detailed the proof of the Pueblo people's geometric sophistication.

Their abilities are exemplified at the Sun Temple archaeological site in Mesa Verde National Park, in Montezuma County, Colo.

"I noticed in my site survey that the same measurements kept popping up over and over again," Sherry Towers, a professor at Arizona State, said in a news release. "When I saw that the layout of the site's key features also involved many geometrical shapes, I decided to take a closer look."

While surveying the expansive layout, Towers and her colleagues found equilateral triangles, squares, 45-degree right triangles, Pythagorean triangles and the "golden rectangle."

The golden rectangle and its eye-pleasing proportions is often employed in the arrangement of pieces of Western art -- the positioning of figures and shapes within a painting, drawing or print. Mathematicians in ancient Greece and Egypt described the unique shape and its aesthetic qualities. Evidence of the golden rectangle has also been found among Mayan art and architecture.

But unlike the Egyptians, Greeks and Mayans, the Pueblos had no written words or numbers with which to make notes -- no guides for building perfectly proportioned multi-room houses and multi-building complexes.

"This is what I find especially amazing," Towers said. "The genius of the site's architects cannot be underestimated. If you asked someone today to try to reconstruct this site and achieve the same precision that they had using just a stick and a piece of cord, it's highly unlikely they'd be able to do it, especially if they couldn't write anything down as they were working."