Problems with the Circle

I didn't just want to copy the circle- I wanted to understand the circle. So when I finally happened upon the formula for a circle (x sq + y sq = 1), to say the least, I was absolutely confused. "So what you're saying to me is that the square of x plus the square of y is always equal to one?" "I guess the one must stand for ' one circle'." Luckily, I was wrong. The true equation for a circle is x sq + y sq = radius sq. The other equation was more of a template. The assumption was that the radius would always be at least one, which is not always true.