Question

Macy described four triangles as shown below:

Triangle A: All angles measure 60°.

Triangle B: All sides have length 6 cm.

Triangle C: Two sides have length 6 cm, and the included angle measures 60°.

Triangle D: Base has length 6 cm, and base angles measure 50°.

Which triangle is not a unique triangle?

Triangle A
Triangle B
Triangle C
Triangle D