Corresponding sides are a pair of matching sides in two different shapes (size does not matter). In the field of geometry, the concept of corresponding sides plays an important role to prove various triangular theorems.
The Boeing B-17 Flying Fortress is a four-engine heavy bomber aircraft developed in the 1930s for the United States Army Air Corps (USAAC).
Definition of flying buttress. : a masonry structure that typically consists of a straight inclined bar carried on an arch and a solid pier or buttress against which it abuts and that receives the thrust of a roof or vault.