Final answer:
To calculate sin(B) in a right-angled triangle, the length of the hypotenuse or the other leg is necessary. Without this information, sin(B) cannot be determined in triangle ABC with a right angle at A and side AB equal to 4 cm.
Step-by-step explanation:
To find sin(B) in right-angled triangle ABC with right angle at A and AB = 4 cm, we need to know the length of the hypotenuse AC or the other leg BC. Without this information, we cannot directly calculate sin(B). However, in a right-angled triangle, sin(B) will equal the length of the opposite side to angle B (which is AB if B is at the right-angle) divided by the length of the hypotenuse. Therefore, if B were the right angle, sin(B) would equal 1 as sin(90°) is always 1. But since the question specifies A is the right angle, we cannot determine sin(B) without additional information about side AC or BC.