The number of angles in Fig. 2.8 is


There are 3 individual angles


Then 2 angles in pair of 2, i.e., 40+20 and 20+30 (40+30 is not considered as it is not continuous)


And then there is one angle which is the pair of all three i.e., 40+20+30.


So in total there are 6 different angles.

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