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.