Shannon said that a triangle with exactly 2 congruent sides and an obtuse angle is an equilateral obtuse triangle. describe her error.

Equilateral means that the 3 sides are equal length. For this to happen, the triangle needs to also have 3 equal angles, but it is mentionned that it has an obtus angle, therefore, not all angles are the same, meaning the 3 sides also aren't equivalent.

the triangle isn't equilateral