Question

How do you find the area if diameter is 12 cm?

Answer 1

I found: `A=113cm^2`

Explanation:

Consider that radius `r` is:
`r=d/2=12/2=6cm`
Area `A` is:
`A=pir^2=3.14*36=113cm^2`

Answer 2

`113cm^2`

Explanation:

I assume you meant "the area of a disk" because you say "diameter" (but it is not so clear from the question, you could have meant the area of a "sphere" (which is in 3D), but I am assuming you are talking about a "disk").

There is a simple formula for the area of a disk:
`Area=pi r^2`
where r is the radius.
The diameter is twice the radius (by definition).
So in our case, since the diameter is 12cm,
the radius is 6cm.

Thus, the Area of a disk of diameter 12cm is:
`Area=pi (6cm)^2=pi*36(cm^2)`
i.e.
`Area = 113 cm^2`

That's it! Hope that helped.