Question

Determine the number of pentagons in the following figure :

(A) 5

(B) 6

(C) 8

(D) 10

Answer 1

The figure may be labelled as follows :

 

In this case, six pentagons have been formed by the combination of three triangles and two rhombuses - ADFHJ, CFHJL, EHJLB, GJLBD, ILBDF and KBDFH. Four other pentagons are formed by the combination of three triangles and one rhombus - LCFHM, LBEHM, BKFHM and BLIFM. Thus, there are 10 pentagons in the figure.