Theatron - place of viewing
Therefore - Amphitheatre is 'a theatre on both sides'
An amphitheatre is a circular theatre NOT semicircular
Source: I studied Latin for three years, but nevertheless, here‘s a proof
"The traditional bow and arrow had long been a specialized weapon that required considerable user training, physical strength and expertise to operate with any degree of practical efficiency. . . . In contrast, the crossbow was the first projectile weapon to be simple, cheap and physically undemanding enough to be operated by large numbers of conscript soldiers, thus enabling virtually any nation to field a potent force of ranged crossbowmen with little expense beyond the cost of the weapons themselves."