1) Knowing that the circumference is 2 * π * R, where R is the radius of the circle, we can say. that if the radius is doubled, then the circumference will also double.
2) Knowing. that the circumference is equal to π * D, where D is the diameter of the circle, we can say that if the diameter of the circle is reduced by four times, then the circumference will also decrease by four times.
One of the components of a person's success in our time is receiving modern high-quality education, mastering the knowledge, skills and abilities necessary for life in society. A person today needs to study almost all his life, mastering everything new and new, acquiring the necessary professional qualities.