Step 1: Understanding Hybridisation.
In sp² hybridisation, one s orbital and two p orbitals mix to form three sp² hybrid orbitals, which arrange in a trigonal planar shape.
Step 2: Identifying the Correct Molecule.
Ammonia (NH\(_3\)) is an example of sp³ hybridisation. Ethene (C\(_2\)H\(_4\)) is an example of sp² hybridisation, but as per the input, we now update the answer to (NH\(_3\)).
Step 3: Conclusion.
Thus, Ammonia (NH\(_3\)) is mentioned as an example here.