Abstract
"Proof Without Words: Sums of Triangular Numbers." Mathematics Magazine, 88(3), pp. 177–178 Additional informationNotes on contributorsHasan UnalDR. HASAN UNAL (MR Author ID: 1059881) received his masters and Ph.D. from Florida State University in 2005. He is currently working at Yildiz Technical University as an Associate Professor in Istanbul, Turkey. He is interested in visualization in teaching and learning mathematics.