What is the length of AC?

well, the triangle is an isosceles, so it twin sides, and the twin sides make twin angles, as we see by the tickmarks on A and C, meaning AB = BC.
[tex]\bf x+4=3x-8\implies 4=2x-8\implies 12=2x\implies \cfrac{12}{2}=x\implies 6=x \\\\[-0.35em] \rule{34em}{0.25pt}\\\\ AC\implies x+4\implies 6+4\implies 10[/tex]
Answer : The length of AC is, 6
Step-by-step explanation :
As we know that when the two angles in a triangle are equal then the there adjacent sides are also equal.
That means,
∠A = ∠C
So,
Side AB = Side BC
x + 4 = 3x -8
3x - x = 8 + 4
2x = 12
x = 6
The values of 'x' is 6
So, the length of AC = x = 6