What is the area of a circle with radius 3 units?

• A. 3π square units
• B. 9π square units
• C. 6π square units
• D. 12π square units

Answer: (B)

The area of a circle depends on the radius squared, described by A = π r^2. With a radius of 3 units, plug in r = 3: A = π × 3^2 = 9π square units. This matches the result expressed as nine times π. The other numbers would come from different radii (for example, an area of 3π would correspond to a radius of √3, 6π to √6, and 12π to √12), so they don’t fit the given radius.