document.write( "Question 3429: If the number of square units in the area of circle C is twice the number of linear units in the circumference of C, what is the number of square units in the area?
\n" ); document.write( "(A) 4
\n" ); document.write( "(B) 8
\n" ); document.write( "(C) 4π
\n" ); document.write( "(D) 8π
\n" ); document.write( "(E) 16π \n" ); document.write( "

Algebra.Com's Answer #1507 by drglass(89) $\"\"$ $\"About$

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The circumfrence of a circle is 2πr and the area is πr². We are told that the area is twice the circumfrence so

\n" ); document.write( "πr² = 2(2πr)

\n" ); document.write( "cancel π from both sides and one r from both sides and you get

\n" ); document.write( "r = 4

\n" ); document.write( "

\n" ); document.write( "check the answer by putting r into both equations and you get:

\n" ); document.write( "π4² = 16π for the area and

\n" ); document.write( "2π4 = 8π for the circumfrence. Clearly, the area is twice the linear measure of the circumfrence. \n" ); document.write( "

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