SOLUTION: 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?
(A) 4
(B) 8
Algebra ->
Circles
-> SOLUTION: 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?
(A) 4
(B) 8
Log On
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?
(A) 4
(B) 8
(C) 4π
(D) 8π
(E) 16π Answer by drglass(89) (Show Source):
You can put this solution on YOUR website! The circumfrence of a circle is 2πr and the area is πr2. We are told that the area is twice the circumfrence so
πr2 = 2(2πr)
cancel π from both sides and one r from both sides and you get
r = 4
check the answer by putting r into both equations and you get:
π42 = 16π for the area and
2π4 = 8π for the circumfrence. Clearly, the area is twice the linear measure of the circumfrence.
(