bán kính 
radius [ bán ] : (1) to sell; (2) half, demi-, semi-, hemi-
[ kính ] : (1) to (show) respect; (2) glass, (eye)glasses
Most Common Compounds Set 1:
Most Common Compounds Set 2 :
vòng tròn 30 km bán kính a circle with a 30 km radius đường bán kính radius (of a circle)