It is impossible for a triangle to have parallel lines because its three angles must add up to 180 degrees, making it impossible for its three sides to not intersect.
A parallel line can never intersect another line, and triangles must always have sides that intersect.
To determine whether two lines are parallel, attempt to connect them with a third line and observe whether it forms a right angle. When connecting two sides of a triangle with a third line, it is never possible to form a right angle. This new line drawn between the sides of parallelograms and other shapes with parallel lines creates right angles.
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