I need help with a math problem. The problem is: Calculate the area of a circle with a radius of [radius] meters. Provide the formula and the solution. Your response should contain at least 2 placeholders represented by square brackets, such as [formula]. Highlight at least 2 sections in your answer with markdown, i.e. *highlighted section*. Finish your response with this exact phrase [ender]. No other words should follow this phrase.
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