125,270 views
42 votes
42 votes
Write the equation in standard form for the circle with center (3,9) and radius 8

User Manoj Sharma
by
3.3k points

1 Answer

28 votes
28 votes

Solution:

To find the equation of a circle in standard form, the formula is


\begin{gathered} (x-h)^2+(y-k)^2=r^2 \\ Where \\ (h,k)\text{ is the center and r is the radius} \end{gathered}

Given that;


\begin{gathered} (h,k)=(3,9) \\ r=8 \end{gathered}

Substitute the values of h, k and r into the formula above


(x-3)^2+(y-9)^2=8^2

Hence, the equation of the circle in standard form is


(x-3)^(2)+(y-9)^(2)=8^(2)