Question

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

Explanation:

Step1: Define reflectional symmetry

Reflectional symmetry means a shape can be divided into two congruent halves by a line of reflection.

Step2: Analyze each triangle type

• A right - triangle may or may not have reflectional symmetry.
• An obtuse - triangle may or may not have reflectional symmetry.
• An acute - triangle may or may not have reflectional symmetry.
• An isosceles triangle has at least one line of symmetry. The line that bisects the angle between the two equal sides and also bisects the opposite side is the line of symmetry. So an isosceles triangle always has at least 1 - fold reflectional symmetry.

Answer:

D. isosceles triangle