Question

which statement describes the order of rotational symmetry for an isosceles triangle?
an isosceles triangle has an order 0 rotational symmetry because there is no angle at which it can be rotated onto itself.
an isosceles triangle has an order 1 rotational symmetry because it does not have all congruent angles.
an isosceles triangle has an order 2 rotational symmetry because it has 1 pair of congruent angles.
an isosceles triangle has an order 3 rotational symmetry because it has 3 angles.

Explanation:

• Rotational symmetry order is the number of times a figure coincides with itself during a \(360^{\circ}\) rotation.
• An isosceles triangle (non - equilateral) has only one way to coincide with itself (when rotated \(360^{\circ}\)), because its angles are not all congruent.

Answer:

An isosceles triangle has an order 1 rotational symmetry because it does not have all congruent angles.