The radius of the circle is 4. Find the diameter of the circle.

According to the generally accepted rule in science, the term “radius” is usually used to denote a quantity called the elements of a circle, which is numerically half of the diameter. In accordance with the above definition, to determine the value of the diameter of a circle, an increase in the known value of its circumference by a factor of 2 is required. Taking into account the above, for the case considered in the initial task, we have:

d = 2r;

d = 2 * 4;

d = 8 (units).