Answer:
x = 3
Explanation:
Since the 3 angles are congruent the triangle is equilateral.
The 3 sides of an equilateral triangle are congruent
Equate AB = AC and solve for x, that is
6x - 3 = 3x + 6 ( subtract 3x from both sides )
3x - 3 = 6 ( add 3 to both sides )
3x = 9 ( divide both sides by 3 )
x = 3