The answer: For more explanation please look at the image. according to the image, the length of line segment AC can be found as the following method shows:
<span>sin(40°)= opposite side / hypotenuse, opposite side = b, hypotenuse = AB= 20cm </span>sin(40°)= b / 20 and this applies, b = 20 x sin(40°) = 0.64*20 = 12.85 cm AC= 12.85 cm