2. An arch is a structure that spans a space while supporting weight Arches appeared as early as the 2nd millennium BC in Mesopotamian brick architecture, but their systematic use started with the Ancient Romans who were the first to apply the technique to a wide range of structures

4. The civilizations Urartian, Egyptian, Babylonian, Greek and Assyrian knew the arch but their use was infrequent and mostly confined to underground structures such as drains where the problem of lateral thrust is greatly diminished The oldest and best arched city gate in the world, eight feet wide, was found in Ashkelon, Israel, and is dated to the middle bronze age.

5. The Romans were the first builders in Europe, perhaps the first in the world, fully to appreciate the advantages of the arch, the vault and the dome EtruscansRomans -Erected arch structures as bridges, gates, aqueductos. - Introduced triumphal arch. - Used Vaults. -Used domed structures. -Invented The Roman Arch or Voussoirs

6. Vault Triumphal Arch Domes Is an architectural term for an arched form used to provide a space with a ceiling or roof is a structure in the shape of a monumental archway, in theory built to celebrate a victory in war, but often used to celebrate a ruler is a structural element of architecture that resembles the hollow upper half of a sphere.

7. Mesoamerican Civilizations -Created various types of Corbelled Arches -Used Trapezoidal Arch

8. The most common is to build a frame (historically, of wood) which exactly follows the form of the underside of the arch. This is known as a centre or centring. The voussoirs are laid on it until the arch is complete and self-supporting.

10. Segmental Arch Triangular Arch Round Arch Unequal Round Arch

11. Lancet Arch Equilateral PointedArch Cusped Arch Jack Arch

12. Horseshoes Arch Three Centered Arch Inflexed Arch Elliptical Arch

13. Ogee Arch Tudor ArchCatenary Arch Reverse Ogee Arch

14. -The size of arches is limited only by economy -They are hard to buttress and to build -Provides a structure which eliminates tensile stresses in spanning an open space -Arches are builded with small, light blocks In bricks as well as stone, which are easy to transport and to handle -By using the arch configuration, significant spans can be achieved

16. Paris; a 19th century triumphal arch modeled on the classical Romandesign The Arc de Triomphe

17. The Gateway Arch in Saint Louis, Missouri; a sculpture based on a catenary arch The Gateway Arch

18. Arch of Constantine,Rome, Italy commemorating a victory by Constantine I in 312 AD Arch of Constantine

19. Arches in the nave of the church in monastery of Alcobaça, Portugal Alcobaça Monastery