Which part of the body was protected by a component of medieval armor called brigandine?

A brigandine is a form of body armour from the Middle Ages. It is a garment, generally heavy cloth, canvas or leather, lined with small oblong steel plates riveted to the fabric.

Medieval brigandines were essentially a refinement of the earlier coat of plates, which developed in the late 12th century, typically of simpler construction made of larger plates. The Asian-originated armour reached Europe after the Mongol invasion in 1240 that destroyed the Kievan Rus' and generated extensive damage to the Kingdom of Hungary in 1241. The new armour became very popular first in Eastern Europe, especially in Hungary, towards the end of the 13th century and after having proved effective was adopted by the medieval states from West Europe several decades later.

Later brigandines first appeared towards the end of the 14th century, but survived beyond this transitional period between mail and plate, and came into wide use in the 15th century, remaining in use well into the 16th. 15th century brigandines are generally front-opening garments with the nails arranged in triangular groups of three, while 16th century brigandines generally have smaller plates with the rivets arranged in rows.