Why did aztecs build chinampas? a. to defend against attackers b. to protect their food stores c. to provide additional farm lands d. to escape the spanish

Aztecs built chinampas ('floating gardens') in order to provide additional farm lands (answer C). The idea was to grow crops in small rectangular areas (ci. 30 x 2.5 m) on shallow lake beds. Aztecs began to use chinampas in Tenochtitlan in about 1250 AD.