What is the cross-sectional area of a piston with diameter 1.5 inches?

What is the cross-sectional area of a piston with diameter 1.5 inches?

• A. 0.589 in^2
• B. 1.77 in^2
• C. 3.14 in^2
• D. 2.25 in^2

Answer: (B)

The area of a circular cross-section comes from the circle area formula, A = π r^2. With a diameter of 1.5 inches, the radius is half of that: r = 0.75 inches. So the area is A = π(0.75)^2 = π(0.5625) ≈ 1.767 square inches, which rounds to 1.77 in^2. This matches the given result. Using the radius ensures the calculation stays consistent with how the diameter relates to area.

The area of a circular cross-section comes from the circle area formula, A = π r^2. With a diameter of 1.5 inches, the radius is half of that: r = 0.75 inches. So the area is A = π(0.75)^2 = π(0.5625) ≈ 1.767 square inches, which rounds to 1.77 in^2. This matches the given result. Using the radius ensures the calculation stays consistent with how the diameter relates to area.