APA (7th ed.) Citation

Foster, C. (2015). Expression polygons. National Council of Teachers of Mathematics.

Chicago Style (17th ed.) Citation

Foster, Colin. Expression Polygons. National Council of Teachers of Mathematics, 2015.

MLA (9th ed.) Citation

Foster, Colin. Expression Polygons. National Council of Teachers of Mathematics, 2015.

Warning: These citations may not always be 100% accurate.