In China, spheres are used to exercise a person's hands. If the diameter of a sphere is 2 inches, how many square inches are in its surface area? Express your answer in terms of $\pi$.
Question:
In China, spheres are used to exercise a person's hands. If the diameter of a sphere is 2 inches, how many square inches are in its surface area? Express your answer in terms of $\pi$.
Answer:
Let's think step by step.

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4\pi
In China, spheres are used to exercise a person's hands. If the diameter of a sphere is 2 inches, how many square inches are in its surface area? Express your answer in terms of $\pi$.
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