What is the length of angle BC?

If you mean side BC (instead of angle BC), then the answer is 22 units.
To get this answer, set the sides AB and AC equal to each other and solve for x
AB = AC
2x - 24 = x - 2
2x-x = -2+24
x = 22
Since BC = x, and x = 22, this means BC is 22 units long.
We have m∠C = m∠B, therefore it's an isosceles triangle.
Therefore we have the equation:
2x - 24 = x - 2 add 24 to both sides
2x = x + 22 subtract x from both sides
x = 22
BC = x