Find the arc length equal to 0.4 times the circumference of a circle with a radius of 2.5 cm.

In order to find the length of the arc, we need to find the length of the original circle. There is a formula for this:

l = 2πr

Where:
l is the circumference;
π – constant equal to 3.14;
r is the radius of the circle.

From the problem statement, we know that the radius of this circle is 2.5 centimeters. Knowing this, we can find the length of a given circle:

l = 2πr = 2 * 3.14 * 2.5 = 15.7 centimeters

Now we need to find the arc length, which is 0.4 of the arc length of the original circle:

larcs = l * 0.4 = 15.7 * 0.4 = 6.28 centimeters