Find the area of a circle if 2/7 of the circumference of this circle is 24.8 cm.

First, find the total circumference:

24.8: 2/7 = 24.8 * 7/2 = 86.8 cm;

Find the radius of the circle through the known circumference (P = 2 * π * R):

R = P / (2 * n) = 86.8 / (2 * 3.1) = 14 cm;

We find the area of a circle using the formula:

S circle = 3.1 * R ^ 2 = 3.1 * 14 * 14 = 607.6 cm ^ 2;

Answer: 607.6 cm ^ 2.