Question

the diameter of a circle is multiplied by 10. how does the circumference change? a it is divided by 10. b it does not change. c it is multiplied by 10. d it is one - fifth as large.

Explanation:

Step1: Recall circumference formula

The circumference \( C \) of a circle is \( C = \pi d \), where \( d \) is the diameter.

Step2: Calculate new circumference

If diameter becomes \( 10d \), new circumference \( C' = \pi (10d) = 10\pi d = 10C \).

Step3: Compare with original

The new circumference is 10 times the original.

Answer:

C. It is multiplied by 10.