Answer
Center of circle is $\left( 0,0 \right)$ and radius is $r=5$.
Work Step by Step
Standard equation of the circle is:
${{\left( x-h \right)}^{2}}+{{\left( y-k \right)}^{2}}={{r}^{2}}$
Where, the center coordinates are $\left( h,k \right)$ and $\left( x,y \right)$ is any point on the circumference and $r$ is the radius of the circle.
And equation of the circle is ${{x}^{2}}+{{y}^{2}}=25$ (equation - 2)
Now compare both the equations.
$\begin{align}
& {{\left( x-0 \right)}^{2}}+{{\left( y-0 \right)}^{2}}=25 \\
& {{\left( x-0 \right)}^{2}}+{{\left( y-0 \right)}^{2}}={{\left( 5 \right)}^{2}} \\
\end{align}$
Center coordinate of the circle is $\left( h=0,k=0 \right)$.
And radius of the circle is $r=5$.
To graph, we plot the points $\left( 0,5 \right)$, $\left( 0,-5 \right)$, $\left( -5,0 \right)$, and $\left( 5,0 \right)$ which are, respectively, 5 units above, below, left and right of $\left( 0,0 \right)$.
