Question

What is the equation of the circle with: center (5, 7) & point on the circle: (-2, 8)?

Answer 1

Answer: (x - 5)^2 + (y - 7)^2 = 50

Explanation:

The general equation for a circle is (x - a)^2 + (y - b)^2 = r^2 where (a, b) is the centre

Use Pythagoras to find r^2

r^2 = (5 - -2)^2 + (7 - 8)^2

= 7^2 + (-1)^2

= 50

So the circle is (x - 5)^2 + (y - 7)^2 = 50