Question

Find two circular objects. Measure the diameter and then make a prediction about the circumference of each circle. How could you check your predictions?

Answer 1

Let's say that the two objects have 5 centimeters and 7 centimeters of diameter.

The circumference of a circle is defined as

$C=\pi d$

Where d is the diameter. Using the measures above, we have

$C_1=\pi(5cm)\approx5\cdot3.14\operatorname{cm}\approx15.7\operatorname{cm}$$C_2=\pi(7\operatorname{cm})=7\cdot3.14\operatorname{cm}=21.98\operatorname{cm}$

Therefore, the circumferences of the measures obtained are 15.7 and 21.98 centimeters.