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Which of the following shapes has only three sets of parallel lines?
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We know that parallel lines are lines that never intersect.
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We often mark parallel lines with these type of arrows.
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When you see two arrows, it’s parallel to the other line that has two arrows.
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Let’s consider the five shapes we were given.
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Shapes b and c have no markings.
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This is because b and c have zero sets of parallel lines.
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They don’t have parallel lines because they have an odd number of sides.
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A triangle has three sides and can’t have any parallel lines.
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A pentagon has five sides and also has no sets of parallel lines.
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So we will cross out these two options.
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Remember how I said that the number of arrows mattered.
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These two sides have one arrow each.
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And it tells us that these two sides are parallel with each other.
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That’s one set of parallel lines.
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And then, we look at the place that has two arrows.
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These two sides are parallel with each other.
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Next, we find the two sides that have three arrows each.
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We can also tell that they are directly across from each other.
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Here’s our third set of parallel lines for shape a.
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Shape a has a fourth set of parallel lines that has four arrows each.
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These two green lines make up the fourth set of parallel lines.
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This octagon is made up of four sets of parallel lines.
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And we’re looking for the shape that has three sets.
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The octagon is not that shape.
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Looking at the square, we find that the square has two sets of parallel lines.
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And finally, we come to the hexagon.
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The sides with one arrow are parallel to each other.
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The sides with two arrows are parallel to each other.
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And the sides with three arrows are parallel with each other.
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The hexagon has three sets of parallel lines.
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This is the shape we were looking for.