Which type of triangle will always have at least 1-fold reflectional symmetry?

An isosceles triangle has at least two equal sides, so reflecting it across the line from the vertex between those sides to the midpoint of the opposite side leaves it unchanged. An equilateral triangle also counts as isosceles and has even more lines of reflectional symmetry. A right, obtuse, or acute triangle does not necessarily have any reflectional symmetry.

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