The area of a circle is,

So pi times the radius squared.
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To find the radius we half to divide the diameter by 2 since the radius is half of the diameter.
The diameter is the line that passes through the the center of the circle going from one side of the circle to the other which is 4 in this case.
Half of 4 is 2 meaning 2 is our radius.
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Plug in the numbers and get,

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I hope that helps you out!!
Any more questions, please feel free to ask me and I will gladly help you out!!
~Zoey
Lines BC, AB, and then AC
Answer:
Its 639 if that dosent help contact me ill help guadianeany time.
Step-by-step explanation:
Answer:
AB = 6.4
Step-by-step explanation:
Assuming that AB + BC is AC, then we can say the following:
AB + BC = AC
AB + 6.8 = 13.2
AB + 6.8 + -6.8 = 13.2 + -6.8
AB = 6.4
Cheers.