Roman architecture was both inventive and derivative. How is the Roman temple related to both Greek and Etruscan designs? What specific aspects are uniquely Roman?
Etruscan is pre-Roman, or early Roman, and is more crude than later Roman structures and styles.
From the following web site: http://employees.oneonta.edu/farberas/arth/arth200/politics/roman_architecture.html
Roman temples, while related to the Greek temple form in general design and use of the Classical orders, represent a very defined category of temple form. The distinctive elements of being raised on a podium, having a front staircase, and having the columns along the sides being attached or engaged (pseudo-peripteral) allow for the easy identification of a Roman temple.
From the following Web site: http://daphne.palomar.edu/mhudelson/studyguides/greekroman_wa.html
GREEK: Post and lintel/marble. ROMAN: True arch (barrel/groin vaults)/concrete.
Web site references/URLs which define the primary stylistic differences between Greek and Roman temple styles.