As the sum of the angles of a triangle is 180 degrees, we can find the measure of Angle A.
180 - 102.9 - 18.6 = 58.5
Now that we know angle A, we can use the Law of Sines to find AB. The angle opposite BC is 58.5 degrees, which we found above. The angle opposite AB is angle C, which is 18.6 degrees.
By the Law of Sines,
AB / sin (18.6) = 943 / sin (58.5)
AB / .31896 = 943 / 0.85264
AB / .31896 = 1105.97652 by simplifying the right side
AB = 1105.97652 * .31896 by multiplying both sides by .31896 and clearing fractions
AB = 352.7622, which is 353 rounded to the nearest whole number.
Thus, AB is 353 feet and choice A is the best answer.
