It is important to know that the standard form of a circle is
[tex](x-h)^2+(y-k)^2=r^2[/tex]Where (h, k) is the center.
According to the given image, the center is (-1,2). So, h = -1 and k = 2.
Also, the radius shown is 2 units. So, r = 2.
Hence, the equation would be
[tex]\begin{gathered} (x-(-1))^2+(y-2)^2=2^2 \\ (x-(-1))^2+(y-2)^2=4 \end{gathered}[/tex]