The radius of the coin is half of its diameter. Therefore, the radius of the coin is:
r = 22 mm / 2 = 11 mm
The circumference of a circle is the distance around its edge, which can be calculated using the formula:
C = 2πr
where π (pi) is a mathematical constant approximately equal to 3.14159. Substituting the value of r from above, we get:
C = 2π(11 mm) ≈ 69.115 mm
So the circumference of the coin is approximately 69.115 mm.
The area of a circle is given by the formula:
A = πr^2
Substituting the value of r from above, we get:
A = π(11 mm)^2 ≈ 380.1327 mm^2
So the area of the coin is approximately 380.1327 square millimeters.