i need help finding the are of a circle. (question in comments)

Question

anonymous · Answer

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anonymous · Answer

You have to take the equation 2pi(r) in which r is the radius (4mm) then just set 2(Pi)(4) and you'll get the answer :)

anonymous · Answer

where did you get 2pi? i don't understand this stuff at all, i was taught differently and my teacher changed it so i don't know how to do it the was she wants it.

anonymous · Answer

It's just an equation for finding the area of a circle :) it's an equation you should know because it'll come up quite often when it comes to circles

anonymous · Answer

my teacher gave me a khan video to watch then I had to do equations and I was good at those then she changed it to stuff I don't know, I tried to use the stuff from the video/khan but I came up with answers that weren't in the options.

anonymous · Answer

huh, that's weird...

anonymous · Answer

okay so I so got the equation wrong. I gave you the equation for finding the circumference of a circle, not the area. But to find the area, you need to use the equation (pi)r^2 sorry!