The diameter of a circle is doubled. By what factor is the area changed?
A)$ \sqrt{2}$
B) 2
C) 4
D) $ \sqrt{4}$
E) 1

Name: The diameter of a circle is doubled. By what factor is the area changed? A)$ \sqrt{2}$ B) 2 C) 4 D) $ \sqrt{4}$ E) 1
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Question

Quizplus · Accepted Answer

The area of a circle is proportional to the square of its radius (A=πr^2). When the diameter of a circle is doubled, the radius is also doubled, and the area is increased by a factor of 2^2 = 4. Thus, the correct answer is C.

The Diameter of a Circle Is Doubled 2 \sqrt{2}2​ B) 2 C) 4 D)

The Diameter of a Circle Is Doubled $\sqrt{2}$ B) 2
C) 4
D)