Answer:
![A = 12.56 cm^(2)](https://img.qammunity.org/2020/formulas/mathematics/middle-school/vocvk6h1l9ak7si6ctg9n59v090fc45u5x.png)
Explanation:
When you want to find area out of diameter. These are the steps you follow:
1. Convert diameter to radius
2. Solve for area
First step:
When you need to convert diameter to radius, you just need to divide by 2
![d = 4cm / 2cm](https://img.qammunity.org/2020/formulas/mathematics/middle-school/5ozx84vudr9me6opsnbmwluw619e0nkyd7.png)
![==> 2cm](https://img.qammunity.org/2020/formulas/mathematics/middle-school/5c9jhjppzbm811iqktq4lo1cwippm0rasn.png)
Second step:
Use formula
![A = \pi * r^(2)](https://img.qammunity.org/2020/formulas/mathematics/middle-school/pjbfzcxq117fp7zwk7nkpxawry5592sgs5.png)
A =
![\pi * 2cm^2](https://img.qammunity.org/2020/formulas/mathematics/middle-school/7wm45hvce9mr8hagxppn3y9p5cwf3vi1rb.png)
A =
![\pi * 4cm](https://img.qammunity.org/2020/formulas/mathematics/middle-school/py77xd7bs0xkob0da1exce1g5in0woec5c.png)
A=
![12.56cm](https://img.qammunity.org/2020/formulas/mathematics/middle-school/d0ehb9uh1ihx8yby21rvmkeblhzhenc0g5.png)