Posted by Anonymous on Sunday, November 13, 2011 at 8:32pm.
Jeff made some designs using equilateral triangles, as shown bellow. He noticed that as he added new triangles, there was a relationship between the number of triangles, and the outer perimeter of the design.
If the pattern is continued, what would be the outer perimeter of a design using 7 triangles?
(Assume the length of a side of a triangle to be 1)

algebra  Anonymous, Sunday, November 13, 2011 at 8:39pm
9