Triangle that has at least two congruent sides.
Properties
- An isosceles triangle has at least one line of symmetry. If it has more than one, then it is an equilateral triangle.
- A non-equilateral isosceles triangle has two congruent angles, which are opposite its congruent sides.If its three angles are congruent, then it is equilateral.
Notation
In the representation of an isosceles triangle, the congruent sides are often marked with hash marks to make them easier to identify and discuss.
Examples
