1. You have that:
r²=(x-h)²+(y-k)²
2. The center of this circle is (0,0), then:
h=0
k=0
3. When you substitute the values of h and k into the equation, you have:
r²=(x-h)²+(y-k)²
r²=(x-0)²+(y-0)²
r²=x²+y²
3. Now, you must find the radius "r".
4. You know that the point is (5,2), so:
r²=x²+y²
5. Finally:
√29=x²+y²
