9514 1404 393
Answer:
2463.01 mm²
2461.76 mm² if you use 3.14 for π
Explanation:
The formula for the area of a circle is ...
A = πr²
where r is the radius, half the diameter.
For a diameter of 56 mm, the radius is 28 mm. Using that in the formula gives an area of ...
A = π(28 mm)² = 784π mm²
For an appropriate value of π, the area is ...
784π mm² = 2463.00864... mm² ≈ 2463.01 mm²
For 3.14 as the value of π, the area is ...
784(3.14) mm² = 2461.76 mm²
_____
Comment on pi
Quite often these problems expect you to use 3.14 for pi. The required answer has 6 significant digits, so the use of a 3-digit value for pi is not appropriate. Rather, the value used should be 3.141493 or even more accurate.