Question

The head of a nail is circular, as shown. The head of this nail has a diameter of 8 millimeters Which measurement is closest to the area of the head of this nail in square millimeters?

Answer 1

The measurement used is "mm²"

Depending on the options provided, here are some answers in decreasing accuracy

16π mm² ; 50.26548 mm² ; 50.24 mm²

Explanation:

To find the area of a circle, you'd use the equation:

A=πr²

And since you have been given a diameter:

d=2r

.: A=π(d/2)²

For the area, you take the unit provided and square it (eg cm to cm²) or just do u² if no units are provided. In your case, it is mm to mm²

All together, we can just replace the variable used with numbers to fill in:

A=π(8/2)²

.:A=π4²

.:A=16π mm²

Lastly, based on how your question is worded, the answer was either the measurement given or you need to simplify.

The measurement would be mm²

If π is typed into a calculator:

A= 50.265482...

If π≈3.14

A= 50.24

I'm also guessing this is multiple choice it is asking for the closest answer, in which case I have listed them in decreasing accuracy above.