(Law of Sines) In △BCD, d = 3, b = 5, and m∠D = 25°. What are the possible approximate measures of angle B? only 90° only 155° 20° and 110° 45° and 135°

≈Law of sines:

   b              d
------- =   ----------
sin(B)       sin(D)

=> sin(B) = sin(D) * b / d

sin(B) = sin(25°) * 5 / 3 ≈ 0.4226 * 5/3 = 0.7043

=> B = arcsine(0.7043) ≈ 45° or 135°

Answer: 45° and 135°