The side of a triangle that forms a side of two given angles.
The angles of a triangle that are not adjacent to a given exterior angle.
1. In a right triangle, the sides opposite the acute angles. 2. In an isosceles triangle, the congruent sides. 3. In a trapezoid, the nonparallel sides.
A triangle with all sides congruent.
An angle formed by one side of a triangle and the extension of another side.
