The answer is x = 3
Explanation:
As shown in the picture, all three angles are equal, so this is an equilateral triangle.
So, AB = AC = BC
To find x, we just pick two sides.
AB = AC
6x - 3 = 3x + 6
6x - 3x = 6 + 3
3x = 9
x = 9/3
x = 3
