Parallel sides are two sides of a shape that run in the same direction and never cross, no matter how far you extend them.
Think of railroad tracks: they are parallel because they stay the same distance apart and never meet.
To identify parallel sides, look for sides that are the same distance apart and do not touch, even if you imagine extending them forever.
Use a ruler or the edge of paper to help you check if lines go in the same direction without crossing.
Different quadrilaterals can have no parallel sides, one pair, or two pairs of parallel sides.
Knowing which quadrilaterals have parallel sides helps you classify and understand their properties.
Recognizing parallel sides helps you solve problems about shapes, such as finding area, perimeter, and classifying quadrilaterals.
Parallel sides are an important clue when naming and comparing quadrilaterals.