the distances are equal because it is the radius of each circle
Equilateral triangle
Step 1
Let
the radius of the circle with center A = red line
distance AC=from the A to the edge of the circle= radius of the circle
distance AB=from the A to the edge of the circle= radius of the circle
Step 2
it is equal for the circle with center in C and B
distance CA= radius of circle C
distance AB= radius of circle C
and the same for B,
hence, all sides are equal it is called Equilateral triangle.
I hope this helps you
