The arch is a curved structural element predominantly loaded with pressure. The bending moment in the arc is very small or ideally absent, where a balance of forces is achieved by compressive thrust against the supports. It is applied in various areas of construction such as bridge construction, tunnel construction, dams, monuments and palaces. One of the first load-bearing systems built in different shapes and from different materials throughout its rich history. Made of stone and masonry arches of the ancient and medieval world, built with traditional geometric rules of proportionality, experience and oral tradition, which even today, with their size, aesthetics and concept, defy the environment. Various further theories and assumptions, of elasticity and plasticity, have created arc calculations by analytical equilibrium methods and especially by graphical pressure line methods which we deal with in this paper. It began with Hooke’s theory of the application of a chain to represent the axis of an arch, the first representation of a pressure line that was later mathematically proven. Finally, Couplet-Heyman's theory presents concrete assumptions, where masonry has no tensile strength, has infinite compressive strength and there is friction in the joints, and also that failure occurs due to the appearance of plastic joints. Such conclusions have made it possible to determine boundary conditions and to determine safety coefficients, significant for comparing environmental affects and material resistance today. The pressure line is the resultant curve of the grip of the compressive forces in the cross sections of the arc. The ideal position of the support line is such that it passes through the axis of the arch because then there is no bending moment, but in reality it is impossible to perform because there is always some deviation either in the material or in the load. Graphical determination of the pressure line is done using an iterative procedure. By dividing the arch into segments, calculating the center of gravity and forces through the same, forming a polygon of forces, boundary horizontal thrusts of forces determining the boundary pressure lines within the contours of the arch. In conclusion, the arch and the calculation of arches by the graphical process brought us a great understanding of the behavior of arcs and the interactions of forces in them and as before the theory of arches changed rapidly it will certainly change in the future.