In the diagram, \Delta{PQR} is equilateral and is made up of four smaller equilateral triangles. If each of the smaller triangles has a perimeter of 9\:cm, what is the perimeter of \Delta{PQR}?
Answer Choices
A. 15\:cm
B. 9\:cm
C. 36\:cm
D. 27\:cm
E. 18\:cm
