A^2 + b^2 + c^2 - ab - bc - ca = 0
a.a + b.b + c.c = a.b + b.c + c.a
equating term by term:-
a = b
b = c
c = a
Therefore a = b = c
Answer:
Root 181
Step-by-step explanation:
Using distance formula, we know that the answer will be the square root of 181. Unfortunately, this is not a perfect square, and it is prime, so that number will remain the same.
Distance Formula: 
Hope this helped!