How many number of TRIANGLES in the following figure :

22 14 21 18

21

The logic followed here is; 01+02= 03 (AOB) 01+02= 03 (DOC) 01+02= 03 (AOD) 01+02= 03 (BOC) 01+02= 03 (BEC) And, the other triangles are; ABD, CBD, ABC, ADC, BOE, COE Therefore, 03+03+03+03+03+06= 21 triangles