Illustration of 10 congruent equilateral triangles that have the same center. Each triangle has been rotated 12° in relation to the one next to it. The outer vertices are connected with a smoother curve to form a circle. Hence, the circle is circumscribed about the triangles. ref. http://etc.usf.edu/clipart/42900/42974/tri2_42974.htm Copyright © 2004–2016 Florida Center for Instructional Technology. ClipArt ETC is a part of the Educational Technology Clearinghouse and is produced by the Florida Center for Instructional Technology, College of Education, University of South Florida.