Given:
Radius = 5 km.
circumference of the circle
[tex]\text{circumference =}2\pi r[/tex]
Substitute r=5 in the formula, we get
[tex]\text{circumference =}2\pi\times5[/tex]
[tex]\text{circumference =}10\pi km[/tex]
The area of the circle is
[tex]\text{Area =}\pi r^2[/tex]
Substitute r=5 in the formula, we get
[tex]\text{Area =}\pi(5)^2[/tex]
[tex]\text{Area =}25\pi km^2[/tex]
Hence the answers are
[tex]\text{circumference =}10\pi km[/tex]
[tex]\text{Area =}25\pi km^2[/tex]
