The diameter of the circle is given 40 cm,
[tex]D=40[/tex]
Consider that the radius 'R' of the circle is half its diameter,
[tex]\begin{gathered} R=\frac{1}{2}\cdot D \\ R=\frac{1}{2}\cdot(40) \\ R=20 \end{gathered}[/tex]
Thus, the radius (JK)) of the circle is 20 centimeters.
Consider that the circumference 'C' of the circle is given by the formula,
[tex]C=2\pi R[/tex]
Substitute the value,
