That is a question about circle area.
To calculate the area of a circle, we multiplicate the constant pi ([tex]\pi \approx 3.14[/tex]) by the radius (of the circle) squared. The expression represents that is below:
[tex]\boxed{A_c = \pi \times r^2}[/tex]
In our problem, we don't know what is the circle raius, but we know the diameter. In a circle, the diameter is equal the double radius.
So, to know the radius of our circle, we divided the diameter by 2. Consequently, the raius of our circle is [tex]63 \div2 = 31.5[/tex].
Now, we should use the expression and we will find the area:
[tex]A_c = 3.14\times 31.5^2\\A_c = 3.14\times 31.5\times 31.5\\A_c =3.14\times 992.25\\A_c = 3115.665[/tex]
Therefore, the area of a circle with a diameter of 63 is approximately 3115.665.
I hope I've helped. :D
Enjoy your studies! \o/
