For a circle with diameter 2 inches, which statement about its cross-sectional area is correct?

For a circle with diameter 2 inches, which statement about its cross-sectional area is correct?

• A. Area is approximately 1.5708 in^2.
• B. Area is approximately 2.0944 in^2.
• C. Area is approximately 3.1416 in^2.
• D. Area is approximately 4.7124 in^2.

Answer: (C)

The key idea is using the circle area formula A = π r^2. A circle’s radius is half its diameter, so with a diameter of 2 inches, the radius is 1 inch. Therefore the area is A = π × (1)^2 = π square inches, which is about 3.1416 in^2. So the cross-sectional area for this circle is approximately 3.1416 in^2. The other numbers would come from different radii, not from a diameter of 2 inches.

The key idea is using the circle area formula A = π r^2. A circle’s radius is half its diameter, so with a diameter of 2 inches, the radius is 1 inch. Therefore the area is A = π × (1)^2 = π square inches, which is about 3.1416 in^2. So the cross-sectional area for this circle is approximately 3.1416 in^2. The other numbers would come from different radii, not from a diameter of 2 inches.