Moc & aacute;rabes are a typical decoration of the artistic tradition of al-Andalus. The aim of this article is to explain the design principles, composition, and construction of the moc & aacute;rabes on the fifteenth-century ceiling of Torrijos, which is preserved in the Victoria and Albert Museum, London. To explain its design, I use the methodology used from the medieval period to the eighteenth century, as recorded in manuscripts and treatises of the seventeenth century. I argue that the key to the design of moc & aacute;rabes does not come from complex mathematical calculations, but from the analysis of the square, since all the pieces are sized in proportion to the side of the square or its diagonal. To do this, approximate proportional values are assigned, giving the side of the square a numerical value of five and the side of the diagonal a numerical value of seven. This method facilitates the design and proportion of the wooden prisms which are necessary for the construction of the moc & aacute;rabes, and the calculation of measurements in general, which is confirmed in the analysis of the composition of the Torrijos ceiling. Los moc & aacute;rabes son una decoraci & oacute;n propia de la tradici & oacute;n art & iacute;stica de al-& Aacute;ndalus. El objetivo de este art & iacute;culo es dar a conocer las pautas del dise & ntilde;o, composici & oacute;n y elaboraci & oacute;n de los moc & aacute;rabes de la armadura del siglo XV de Torrijos que se conserva en el Museo Victoria and Albert, Londres. Para explicar su dise & ntilde;o, usamos la metodolog & iacute;a utilizada desde la Edad Media hasta el siglo XVIII, recogida en manuscritos y tratados del siglo XVII. Sostengo que la clave del dise & ntilde;o de los moc & aacute;rabes, no resulta de complejos c & aacute;lculos matem & aacute;ticos, sino del an & aacute;lisis del cuadrado, pues todas las piezas se dimensionan proporcionalmente al lado del cuadrado o a su diagonal. Para ello, se asignan valores proporcionales aproximados, otorgando al lado del cuadrado, valor num & eacute;rico de cinco y al de la diagonal, valor num & eacute;rico de siete. Este m & eacute;todo facilita el dise & ntilde;o y proporcionado de los prismas de madera necesarios para la construcci & oacute;n de los moc & aacute;rabes, y el c & aacute;lculo de medidas, en general, que se confirma en el an & aacute;lisis de la composici & oacute;n de la armadura de Torrijos.
