is anyone in geometry (10th-grade math)? I need some help

Answer:
angleB = 41.4°
Step-by-step explanation:
✨ Trigonometry✨
cos theta = adj / hyp
theta = inverse-cos adj / hyp
theta = inverse-cos 12 / 16
theta = inverse-cos .75
theta = 41.4°
*theta is the 0 with a line through it