 The geometric designs in Islamic art are often built on combinations of repeated squares and circles , which may be overlapped and interlaced , as can arabesques ( with which they are often combined ) , to form intricate and complex patterns , including a wide variety of tessellations . These may constitute the entire decoration , may form a framework for floral or calligraphic embellishments , or may retreat into the background around other motifs . The complexity and variety of patterns used evolved from simple stars and lozenges in the ninth century , through a variety of 6- to 13 @-@ point patterns by the 13th century , and finally to include also 14- and 16 @-@ point stars in the sixteenth century . 
