Do all isosceles trapezoids have reflectional symmetry?

Yes, all isosceles trapezoids have reflectional symmetry. This symmetry occurs along a vertical line that bisects the shape, passing through the midpoints of the two bases. The two non-parallel sides are equal in length, ensuring that one half mirrors the other across this line of symmetry. Thus, an isosceles trapezoid can be folded along this line, and the two halves will match perfectly.