Every time, these days, it seems, an equation gets forced. . . .
At Poets.org, as at many poetry websites, there is an opportunity to search -- using, for example, "geometry" or "equation" -- and to find lots of poems with mathematical connections.
Carol Dorf is a retired math teacher and a wonderful poet; this link leads to poems from her published in this blog and this link leads to "Wild Equations," a collection of some the mathy poems found in TalkingWriting.
An ongoing source of original and delightful math-poetry is the Journal of Humanistic Mathematics. Visit often and explore!
AND, one more item . . . Recently I revisited Issue 17 (Released November 1, 1917) of The Cordite Poetry Review which has the theme "Mathematics." That issue is online here. Many of the poems seem at first quite distant from the theme -- but browsing the collection of 60 poems (selected by Fiona Hile) has proved thought-provoking. Here is a sample, "Venn Diagram" by Caroline Williamson.