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

Let’s use the formula for the circumference of a circle l = 2 * π * r, where r is the radius of a given circle.
According to the condition of the problem, 2/7 of the circumference of the circle is equal to 24.8 cm, therefore, the following relation holds:
(2/7) * 2 * π * r = 24.8.
We solve the resulting equation and find the radius of the circle r:
(4/7) * π * r = 24.8;
r = 24.8 / ((4/7) * π);
r = 24.8 * 7 / (4 * π);
r = 6.2 * 7 / π;
r = 43.4 / π.
Using the formula for the area of a circle S = π * r², we get:
S = π * (43.4 / π) ² = 43.4² / π = 1883.56 / π.

Answer: The area of a circle is 1883.56 / π cm².