Based on the figure, we can see the following:
Hypothenuse length = 24 units
Angle A = 30 degrees
Side x = opposite of Angle A
Visiting the formula of the trigonometric function:

From the given information: hypothenuse, angle A, and the opposite side, we can use the sin function to solve for the value of x.

Therefore, the length of BC or the value of x is 12 units.