Answer:
![(x-2)^2+(y+5)^2=36](https://img.qammunity.org/2021/formulas/mathematics/college/tyk730d6tbtl564vcoirjofuvr38w1tsk2.png)
Explanation:
The standard form of a circle is given by the equation:
![(x-h)^2+(y-k)^2=r^2](https://img.qammunity.org/2021/formulas/mathematics/middle-school/3gezmntbbjw0kxpks4y5gde90ue9dh956u.png)
Where (h, k) is the center and r is the radius.
We know that the center is (2, -5). So, we can substitute 2 for h and -5 for k. This yields:
![(x-(2))^2+(y-(-5))^2=r^2](https://img.qammunity.org/2021/formulas/mathematics/college/e0hrj3gssixtksg3jn780bnoe37zbmhu16.png)
Simplify:
![(x-2)^2+(y+5)^2=r^2](https://img.qammunity.org/2021/formulas/mathematics/college/nht7dz1oax7njigfxzlfswdriogc0lvgtx.png)
Now, we need to determine r. We know that a point on the circle is (-4, -5). Thus, we can determine r by substituting -4 for x and -5 for y. This yields:
![(-4-2)^2+(-5+5)^2=r^2](https://img.qammunity.org/2021/formulas/mathematics/college/80o3cazlt5nz7110yjpfl6u94z61y4emif.png)
Evaluate:
![(-6)^2+(0)^2=r^2](https://img.qammunity.org/2021/formulas/mathematics/college/ob0tgcvtw73d8btpk8nkoq9vr8gl37j8rt.png)
Evaluate:
![36=r^2](https://img.qammunity.org/2021/formulas/mathematics/middle-school/fe0efm3bhsjw366k3xxxka5nyx4pysz63a.png)
Hence, the radius squared is 36.
We do not actually need to solve for r, as we will square it anyways.
We will substitute 36 for r squared. Hence, our equation is:
![(x-2)^2+(y+5)^2=36](https://img.qammunity.org/2021/formulas/mathematics/college/tyk730d6tbtl564vcoirjofuvr38w1tsk2.png)
The radius will thus be 6 units.