Tina described four triangles as shown below:

Question

Triangle A: All sides have length 12 cm.
Triangle B: Two sides have length 10 cm, and the included angle measures 60°.
Triangle C: Base has length 15 cm, and base angles measure 40°.
Triangle D: All angles measure 60°.

Which triangle is not a unique triangle? Triangle A

Triangle B

Triangle C

Triangle D

Answer 1

Triangle D