The equation of a circle `C`

is

.`expr(["+", X2T, Y2T])` = `R * R`

What are its center `(h, k)`

and its radius `r`

?

`(h, k) = (`

`H``,`

`K``)`

`r`

= `R`

The equation of a circle with center `(h, k)`

and radius `r`

is `(x - h)^2 + (y - k)^2 = r^2`

.

We can rewrite the given equation as `(x - `

.`negParens(H)`)^2 + (y - `negParens(K)`)^2 = `R`^2

Thus, `(h, k) = (`

and `H`, `K`)`r = `

.`R`