Answer: B. An isosceles triangle has an order 1 rotational symmetry because it does not have all congruent angles. dd
Step-by-step explanation:
An isosceles is a triangle that has two sides of equal length.
The isosceles theorem says that the angles opposite to the equal sides of a triangle are equal.
Thus, it also has two equal angles and one non equal angle. Thus, it does not have all congruent angles.
- The order of rotational symmetry of a figure is the number of times we rotate up to 360° the figure such that it looks exactly the same as the original figure.
When we rotate the isosceles triangle up to 360° , only 1 time it looks exactly same as in the beginning because at each rotation the order of angles changes.
Therefore, An isosceles triangle has an order 1 rotational symmetry because it does not have all congruent angles.
