Question

If $(3,-2)$ is on a circle with center $(-1,1)$, then the area of the circle is:

• A. $5\pi$
• B. $55\pi$
• C. $25\pi$
• D. $35\pi$

Answer 1

Answer: (C)

Distance from the center of a circle to any point on the circle is the radius of the circle.

Thus, the distance between $(3,-2)$ and $(-1,1)$ is

$r=\sqrt{(3+1{)}^2+(-2-1{)}^2}$

$=\sqrt{16+9}$

$=5$

Thus, area of the circle $=\pi 5^2$

$=25\pi$