Math Is Fun Forum

I have a 2nd grader who brought home a workbook page from harcourt math book and I have no help to give him on this assignment. The only instructions are to "write a title for each group of plane shapes."  There are 4 sets of shapes. I saw another person had the same problem back in January by tmoye, but did not know how the answers came about to explain them to him. Please help me out. I am new to this site and will most likely use it again in the future. THANKS