What I Learned in Math Todaymorgany2015 on January 18, 2016 Today in math class I learned how to calculate an irregular shape. Calculations: 9 x 3.5 = 31.5 x 4 = 126 9 x 9 = 81 13 x 8 = 104 x 2 = 208 20.5 x 8 = 164 x 2 = 328 20.5x 13 = 266.5 x 2 = 533 – 81 = 452 126 + 81 + 208 + 328 + 452 = 1195cm2