Answer:
∠ B = 48°
Explanation:
∠ A and ∠ B are Alternate angles and congruent, thus
5x - 12 = 2x + 24 ( subtract 2x from both sides )
3x - 12 = 24 ( add 12 to both sides )
3x = 36 ( divide both sides by 3 )
x = 12
Thus
∠ B = 2x + 24 = 2(12) + 24 = 24 + 24 = 48°