Question

1. because all circles are similar, set up a proportion of the circumference to the diameter for the two circles shown in the diagram. $\frac{c_1}{d_1}=\frac{c_2}{d_2}$ 2. suppose $d_1 = 1$. by definition, what is the circumference of the smaller circle? $c_1=$ 1 $pi$ $2pi$ check

Explanation:

Step1: Recall circle - circumference formula

The formula for the circumference of a circle is $C=\pi d$, where $C$ is the circumference and $d$ is the diameter.

Step2: Substitute $d = d_1=1$ into the formula

When $d = 1$, $C_1=\pi\times d_1$. Since $d_1 = 1$, then $C_1=\pi$.

Answer:

$\pi$