Can someone show me how to find the area of one slice of a pizza with 12” in diameter?

I got this far:
Interior angle = 360°/12 = 30°
Arc length = a/360°(πd)

But what’s the next step?

Question

Can someone show me how to find the area of one slice of a pizza with 12” in diameter? 

I got this far:
Interior angle = 360°/12 = 30°
Arc length = a/360°(πd)

But what’s the next step?

anonymous · Answer

How many slices?

anonymous · Answer

Assume n slices, then you want 1/n  * Circle area ->

1/n  * pi*radius^2

anonymous · Answer

I'm really sorry I left this out and didn't reply! It was 12 slices though

anonymous · Answer

but i'm still a little confused..