Answer
The compound has 4 geometric isomers. The structures are drawn and labeled in the attached image.
Work Step by Step
The compounds has 4 geometric isomers: $(2E,4E)-3-ethylhexa-2,4-diene$, $(2Z,4E)-3-ethylhexa-2,4-diene$, $(2E,4Z)-3-ethylhexa-2,4-diene$, $(2Z,4Z)-3-ethylhexa-2,4-diene$ The structures are drawn and labeled in the attached image.