求翻译：今天没发生什么特别或有趣的事。不过今天我们考数学，老师没来就是了。代课老师在上面画了三角形或长方形，求它们的面积和边长。这些还好点，就是立方的好难啊。我完全搞不懂哪的是prism，哪个是cylinder。唉，数学就是难，不属于我这种头脑简单的。是什么意思？

Not nothing special or interesting things happened today. But today we study mathematics, teachers didn't come shot. Substitute teacher drew a triangle or rectangle above, seek their area and length. Fortunately, these points is the cube so difficult. I do not understand completely what is Prism, which is a cylinder. Alas, the math is difficult, simple do not belong to me.