Question

Reasoning Find the circumferences of the two circles. Circle A has a radius of 21 meters and Circle B has a radius of 28 meters. Use pencil and paper. Is the relationship between the radius of a circle and the distance around the circle the same for all circles? Explain.The circumference of Circle A is meters.(Type an exact answer in terms of t.)Please help !!

Answer 1

Circle A

Given data

Radius r = 21 m

$\begin{gathered} \text{Circumference of circle A = 2}\pi r \\ \pi\text{ = }\frac{22}{7} \\ \text{Circumference of A = 2 }\times\text{ }\frac{22}{7}\text{ }\times\text{ 21} \\ =\text{ }\frac{2\text{ }\times\text{ 22 }\times\text{ 21}}{7} \\ =\frac{924}{7} \\ =\text{ 132 m} \end{gathered}$

Circle B

Given data

Radius r = 28 m

$\begin{gathered} \pi\text{ = }\frac{22}{7} \\ \text{Circumference of circle B = 2}\pi r \\ =\text{ 2 }\times\frac{22}{7}\text{ }\times\text{ 28} \\ =\text{ }\frac{2\text{ }\times\text{ 22 }\times\text{ 28}}{7} \\ =\text{ }\frac{1232}{7} \\ =\text{ 176 m} \end{gathered}$

The relationship between the radius and distance around a circle is the same for all circles because the distance around a circle depends on the radius of the circle.