Find the number of triangles in the given figure.
A.
11
B.
13
C.
15
D.
17
Correct answer is C
The figure may be labelled as shown.
The simplest triangles are AFB, FEB, EBC, DEC, DFE and AFD i.e. 6 in number.
The triangles composed of two components each are AEB, FBC, DFC, ADE, DBE and ABD i.e. 6 in number.
The triangles composed of three components each are ADC and ABC i.e. 2 in number.
There is only one triangle i.e. DBC which is composed of four components.
Thus, there are 6 + 6 + 2 + 1 = 15 triangles in the figure.
