Which statement is true about subduction zones?

They always occur at convergent plate boundaries.

I hope this helps!

The length of the arc between consecutive vertices is:

Step-by-step explanation:

The angle between consecutive vertices is 60°, it is because it forms an equilateral triangle.

Now, the length arc is defined as:

Where:

We see the angle is in grades, but we need to convert it to radians.

Finally, the length of the arc between consecutive vertices will be:

I hope it helps you!