The Fons & Porter Half & Quarter Ruler is an easy to use ruler that takes the math out of cutting half-square and quarter-square triangles. It lets you cut both types of triangles from strips rather than by cutting squares diagonally into triangles. You can cut squares from the same strips that you used for triangles. Cut perfect triangle from strips measuring 1" to 5" in width. Ruler features an acrylic construction with easy to follow black and yellow markings. Made in USA.