Answer:
6 millimeters
Step-by-step explanation:
A = L × W
A ÷ L = W
42 ÷ 7 = 6
113.0973355
using this formula: 2 π r^2 + 2 π r h
angle 9 = 55°
angle 7 = 145°
angle 3 = 35°
angle 4 = 55°
Correct me if I'm wrong. I hope it helps.