Step-by-step explanation:
Before we answer, the area of a Circle given it radius is
[tex]a = \pi r {}^{2} [/tex]
The area of a circle given it diameter is
[tex]a = \pi( \frac{d}{2} ) {}^{2} [/tex]
So let answers question 1-4.
1. The area is
[tex]1024\pi[/tex]
2. The area is
[tex]576\pi[/tex]
3.
[tex]1.225\pi[/tex]
4.
[tex]309.76\pi[/tex]
For the 5th problem, circumference is
[tex]\pi \times d[/tex]
where d is the diameter and
[tex]2\pi r[/tex]
where r is the radius.
A circumference of 100 m means the radius is 50 because
[tex]2\pi \times r = 100\pi[/tex]
[tex]r = 50[/tex]
So this means the area is
[tex]2500 {\pi}[/tex]
