Which type of triangle will always have at least 1 -fold reflectional symmetry? right triangle obtuse triangle acute triangle isosceles triangle

The correct answer is **isosceles triangle**. **Explanation:** - **Isosceles Triangle:** By definition, an isosceles triangle has at least two sides that are equal in length. This equality ensures that there is a line of symmetry that bisects the angle between the two equal sides, creating two mirror-image halves. Therefore, every isosceles triangle has at least one line of reflectional symmetry. - **Right Triangle:** Only isosceles right triangles have reflectional symmetry. A general right triangle (scalene right triangle) does not necessarily have any line of symmetry. - **Obtuse Triangle:** These triangles do not inherently possess any symmetry unless they are isosceles. - **Acute Triangle:** Similar to obtuse triangles, acute triangles do not inherently have any line of symmetry unless they are isosceles. **Conclusion:** Among the given options, only isosceles triangles are guaranteed to always have at least one line of reflectional symmetry. **Answer:** isosceles triangle