Three identical circular coins are lined up in a row. The distance between the centers of the first and third coins is 3.2 centimeters. We need to find the radius of one of these coins.

1. Problem Description

Three identical circular coins are lined up in a row. The distance between the centers of the first and third coins is 3.2 centimeters. We need to find the radius of one of these coins.

2. Solution Steps

Let $r$ be the radius of each coin. Since the coins are identical, they all have the same radius. The distance between the center of the first coin and the center of the second coin is $2r$, and the distance between the center of the second coin and the center of the third coin is also $2r$. Therefore, the distance between the center of the first coin and the center of the third coin is $2r + 2r = 4r$.

We are given that the distance between the centers of the first and third coins is 3.2 centimeters. So we have the equation:

$4r = 3.2$

To find the radius $r$, we divide both sides of the equation by 4:

$r = \frac{3.2}{4}$

$r = 0.8$

Thus, the radius of one of these coins is 0.8 centimeters.

3. Final Answer

0. 8 cm