Am, you showed how everything should be questioned. On the other hand, the context of this thread is teaching kids. When I think about a kid discovering the "truth" about the area inside of a circle, I think about a kid taking out a piece of string and a ruler and performing experiments. If we're going to debate the "truth" about the area inside of a circle by using higher level math, then kids will remain confused and will happily go back to their texting.