Let's label the figure.
![](https://df0b18phdhzpx.cloudfront.net/ckeditor_assets/pictures/1595115/original_Slide_13-01_%281%29.png)
The simple triangles are IEF, IED, AGF, AGB, BGE, EFG, BHE, BHC, CHD, and DEH. There are 10 simple triangles in the figure.
![](https://df0b18phdhzpx.cloudfront.net/ckeditor_assets/pictures/1595123/original_Slide_13-02.png)
The triangles composed of two components each are IFD, AFE, ABE, BAF, BEF, EBC, CDE, BDE, and BCD. There are 9 such traingles.
![](https://df0b18phdhzpx.cloudfront.net/ckeditor_assets/pictures/1595126/original_Slide_13-03.png)
The triangles composed of three components each are IFB and IDB. There are 2 such triangles.
The triangles composed of three components each are FDB and ACE. There are 2 such traingles.
![](https://df0b18phdhzpx.cloudfront.net/ckeditor_assets/pictures/1595129/original_Slide_14-02.png)
Total number of triangles in the given figure = 10 + 9 + 2 + 2 = 23