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).
Barrage balloon. A barrage balloon, sometimes called a blimp, is a large balloon tethered with metal cables, used to defend against aircraft attack by damaging the aircraft on collision with the cables, or at least making the attacker's approach more difficult.