Solve Geometry Applications: Circles and Irregular Figures: exemplo 9.42

Problema e solução em inglês, como no livro original.

A circular table has a diameter of four feet. What is the circumference of the table?

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Find the circumference of a circular fire pit whose diameter is $5.5$ feet.

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Step 1. Read the problem. Draw the figure and label it with the given information.
Step 2. Identify what you are looking for.	the circumference of the table
Step 3. Name. Choose a variable to represent it.	Let c = the circumference of the table
Step 4. Translate. Write the appropriate formula for the situation. Substitute.	$C = π d$ $C = π (4)$
Step 5. Solve the equation, using 3.14 for $π .$	$C \approx (3.14) (4)$ $C \approx 12.56 feet$
Step 6. Check: If we put a square around the circle, its side would be 4. The perimeter would be 16. It makes sense that the circumference of the circle, 12.56, is a little less than 16.
Step 7. Answer the question.	The diameter of the table is 12.56 square feet.

Step 1. Read the problem. Draw the figure and label it with the given information.
Step 2. Identify what you are looking for.	the circumference of the table
Step 3. Name. Choose a variable to represent it.	Let c = the circumference of the table
Step 4. Translate. Write the appropriate formula for the situation. Substitute.	$C = π d$ $C = π (4)$
Step 5. Solve the equation, using 3.14 for $π .$	$C \approx (3.14) (4)$ $C \approx 12.56 feet$
Step 6. Check: If we put a square around the circle, its side would be 4. The perimeter would be 16. It makes sense that the circumference of the circle, 12.56, is a little less than 16.
Step 7. Answer the question.	The diameter of the table is 12.56 square feet.