Question

Disha states that the circumference and the area of the larger circle are both double the

circumference and the area of the smaller circle. Is she correct? Explain why or why not.
D
10
10

Answer 1

If the radius of a circle is doubled, the area of the circle will be quadrupled and the circumference will also be doubled. This makes sense because the area of a circle is directly proportional to the square of the radius of the circle (if the radius of a circle is increased x times, its area will be increased to x^2 times the original area), whereas the circumference is proportional to the size of the radius (if the radius of a circle is increased x times, its circumference will increase x times).