The accompanying figure depicts the structures of two isomers, stearic acid and linoleic acid. Based on the structure,
acid is an unsaturated fatty acid.

Linoleic acid is an unsaturated fatty acid.

Explanation: Fatty acids are carboxylic acids with long long chains of hydrcarbons whose hydrocarbon chains can be straight (linear) or branched, saturated or unsaturated.

Saturated fatty acids are those fatty acids in which all the carbon-carbon bonds are single bonds while unsaturated fatty acids in which there is presence of one or more double bonds. When a fatty acid contains only one carbon-carbon double bond, it is said to be monounsaturated but when it contains more than one carbon-carbon double bond, it is said to be polyunsaturated.

From the diagram above, Linoleic acid has two carbon-carbon double bonds, there it is unsaturated.