Final answer:
The diameter of the circle is 20.
Step-by-step explanation:
The equation given is of the form (x - h)² + (y - k)² = r², the standard form of the equation of a circle with center (h, k) and radius r. By comparing the given equation with the standard form, we can see that the center of the circle is (0, 2) and the radius is 10. To find the diameter, we multiply the radius by 2, so the diameter of the circle is 20.
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