Answer:
The length of AB is 7.45 units.
Step-by-step explanation:
You can find the length of AB using Cosine Rule, cosθ = adj./hypo. :
θ = 20°
adj. = 7 units
hypo. = AB
cos 20° = 7/AB
AB = 7/cos 20°
= 7.45 units (3s.f)
7.45
