Meg described four triangles as shown below: Triangle P: All sides have length 7 cm. Triangle Q: Two angles measure 55°. Triangle R: Two sides have length 8 cm, and the included angle measures 60°. Triangle S: Base has length 8 cm, and base angles measure 55°. Which triangle is not a unique triangle? (5 points)

Triangle Q is not a unique triangle because only two angles are given, meaning there can be multiple triangles with those angle measurements.