Question

A circle has its center at (−2, −3) and a radius of 3 units. Find the equation of the circle using the Pythagorean Theorem.

Answer 1

The template for circle equations is: ${ (x - h)}^{2} + {(y - k)}^{2} = {r}^{2}$ where the center is (h, k).

So actually you don't need Pythogarean theorem while constructing the equation.

The given center is (−2, −3), and radius is 3. When we plug those in: ${(x - ( - 2))}^{2} + {(y - ( - 3))}^{2} = {3}^{2} => {(x + 2)}^{2} + {(y + 3)}^{2} = 9$ is your circle equation.