Question

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

right triangle
obtuse triangle
acute triangle
isosceles triangle

Answer 1

An isosceles triangle will always have at least 1-fold reflectional symmetry. This is because an isosceles triangle has at least two sides of equal length, and the line of symmetry can be drawn through the vertex opposite the base and bisecting the base, resulting in two mirror-image halves.

In contrast, a right triangle, obtuse triangle, or acute triangle may or may not have reflectional symmetry depending on the specific measurements of their angles and sides. Therefore, the correct answer is:

**Isosceles triangle**.