The evolution of traditional Arabic calligraphy, a fundamental element of Islamic art, has been influenced by contemporary advancements and the digitization of fonts, resulting in a departure from its original essence. Traditional Arabic calligraphy necessitates the expertise of highly skilled calligraphers who are well-versed in its artistic and technical aspects. This study investigates the proportions of Arabic calligraphy and endeavours to employ the geometry used in Islamic art and architecture to fabricate digital Arabic typographic letters. This research aims to advance the development of digital Arabic typography via the utilization of octagonal geometric patterns, inspired by the Kufic script located in the inner octagon of the Dome of the Rock in Jerusalem. The primary objective concerns the employment of geometry to create digital Arabic typefaces which preserve the proportions of traditional letters while adapting them for various applications such as printed designs, paragraph texts, and titles across a diversity of computer programs. By adopting geometric analysis methods, this research investigates the congruence between the architectural geometry of the octagonal shape and the geometric structure inherent in traditional Arabic calligraphy. Additionally, this research intends to assess the feasibility of applying these proportions to construct digital Arabic typographic letters which are derived from the octagonal systemic geometry found in the Dome of the Rock in Jerusalem.