Does the structure below exhibit geometric isomerism? ch3 tally1 ch3― c ―ch═ch―ch3 tally1 ch3

            YES! The given compound exhibit Geometrical Isomerism.

Explanation:
                   In Geometrical Isomerism or Cis-Trans Isomerism, isomers possess same molecular formula, same structural formula with a double bond and with a only difference in the arrangement of atoms or group of atoms about the double bond in three dimensional space.
                   4,4-dimethylpent-2-ene (given problem) has two groups about the double bond i.e. Methyl (CH₃-) and tertiary Butyl [(CH₃)₃-C-]. In cis configuration both groups are at same side of the double bond, while in trans configuration both groups are located opposite to each other as shown below,