Determine whether the following graphs have a euler circuit

Determine whether the following graphs have a euler circuit. if it does,state the circuit. If not sate why the circuit doesnt exist.

Solution

Graph I is Euler as there is a circuit using one edge once,.

as e1, e2, e3, e4, e5 ,e6,e7 and e8

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Graph B is not Euler as

v1v2v3v4again v1 then v3 v7 v6 etc is good. But at v8 problem comes to have a unique path.

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Not Euler

In the path abcdefghia, some edges namely df, ch, bh are left.