How are the radii of 2 two concentric circles related to the distance between them?

I tried making an equation using their cirmcumferences but I was way off. All I did was subtract the inner circle's circumference from the outer circle's circumference and set it equal to the distance between them and I know that would never work

Not too sure if I understand the question correctly"the distance between them" ?

who is the "them", the circles ?

e.g. radius of first circle = 8
radius of second circle = 3
difference between them is 5

So the distance between them is the difference of the two radii.

To understand the relationship between the radii of two concentric circles and the distance between them, we need to first define some terms.

Let's assume we have two concentric circles: an outer circle with radius R and an inner circle with radius r. The distance between them, which we'll call d, is the length of the line connecting the centers of the two circles.

Now, imagine drawing a line segment from the center of the inner circle to a point on its circumference. This line segment is equal to the radius r. Similarly, if we draw a line segment from the center of the outer circle to a point on its circumference, this line segment would be equal to the radius R.

If we look at the line connecting the centers of both circles, we can see that it forms a right-angled triangle with the two radii as its legs. The distance between the circles, d, is the hypotenuse of this triangle.

According to the Pythagorean theorem, in a right-angled triangle, the square of the hypotenuse is equal to the sum of the squares of the other two sides. In this case, we can write this relationship as:

d^2 = r^2 + R^2

To find the relationship between the radii r and R, we rearrange the equation:

R^2 = d^2 - r^2

Taking the square root of both sides, we get:

R = sqrt(d^2 - r^2)

So, the radius of the outer circle is equal to the square root of the difference between the distance between the two circles squared and the radius of the inner circle squared.

In summary, the radii of two concentric circles are related to the distance between them by the equation R = sqrt(d^2 - r^2), where R is the radius of the outer circle, r is the radius of the inner circle, and d is the distance between the centers of the two circles.