Respuesta :
The required solution is the circumference of the circle for the given radius or diameter
The formula for the circumference of a circle with radius r is :
[tex]C\text{ = 2 }\pi\text{ r}[/tex]The formula for the circumference of a circle with diameter d is:
[tex]C\text{ = }\pi\text{ d}[/tex]For the first circle with a radius of 12m:
[tex]\text{Circumference = 2}\times\text{ }\pi\text{ }\times\text{ 12 = 24}\pi[/tex]For the second circle with a diameter of 18in :
[tex]C\text{ = }\pi\text{ }\times\text{ 18 = 18}\pi[/tex]For the third circle with a radius of 2.8ft:
[tex]\begin{gathered} C\text{ = 2 }\times\text{ }\pi\times\text{ 2.8 } \\ =\text{ 5.6}\pi \end{gathered}[/tex]For the fourth circle with a diameter of 35km:
[tex]\begin{gathered} C\text{ = }\pi\text{ d} \\ =\text{ }\pi\text{ }\times\text{ 35 = 35}\pi \end{gathered}[/tex]For the fifth circle with a radius of 7mm:
[tex]\begin{gathered} C\text{ = 2 }\times\pi\times\text{ r} \\ =\text{ 2 }\times\text{ }\pi\text{ }\times\text{ 7} \\ =\text{ 14}\pi \end{gathered}[/tex]For the sixth circle with a radius of 15.6 cm:
[tex]\begin{gathered} C\text{ = 2}\pi r \\ =\text{ 2 }\times\text{ }\pi\text{ }\times\text{ 15.6 } \\ =\text{ 31.2 }\pi \end{gathered}[/tex]Note: Circumference has a unit. It's unit depends on the unit of the radius/ diameter
