Find the number of triangles in the given figure.
A.
27
B.
25
C.
23
D.
21
Correct answer is A
The figure may be labelled as shown.
The simplest triangles are GLK, DLJ, DJM, HMN, QRE, IRA, IPA and FPO i.e. 8 in number.
The triangles having two components each are BDO, CDQ, DLM, PRA, KFI, NEI, HJI, GJI, DKI and DNI i.e. 10 in number.
The triangles having four components each are DIE, DFI, DOA, DQA andGHI i.e. 5 in number.
The triangles having six components each are DCA and DBA i.e. 2 in number.
DEF is the only triangle having eight components.
ABC is the only triangle having twelve components.
Thus, there are 8+10+ 5 + 2+1 + 1 = 27 triangles in the figure.
