Final answer:
The base area of a cylinder with a radius of 3.9 is approximately 48 m², rounded to two significant figures using the formula A = πr².
Step-by-step explanation:
The question asks for the area of a cylinder, which could potentially mean either the surface area or the cross-sectional area at one end. However, given the details provided, I will assume you are asking for the area of the circular base, commonly referred to as the cross-sectional area or base area of the cylinder.
To find the base area of a cylinder, we use the formula A = πr², where A is the area and r is the radius of the circular base. Using the given radius of 3.9, the calculation would be as follows:
A = π(3.9)^2
A = 3.1415927… × (3.9)^2
A = 3.1415927… × 15.21
A = 47.75399…
Since the radius value has two significant figures, we should round the area to match that precision. Therefore, the area of the cylinder's base is approximately 48 m², rounded to two significant figures. This is the value you would get if you were using a standard scientific calculator with a modest number of available digits.