Given:
The satang coin from Thailand has a radius of about 7 mm.
We need to determine the diameter and circumference of the coin.
Diameter of the coin:
The diameter of the coin can be determined by multiply the radius by 2.
Thus, we have;

Substituting r = 7, we get;


Thus, the diameter of the coin is 14 mm.
Circumference of the coin:
The circumference of the coin can be determined using the formula,

Substituting
and
, we get;


Thus, the approximate value of the circumference of the coin is 43.96 mm