About this video
The video names quadrilaterals as specifically as possible from the given data. Two pairs of parallel sides make a parallelogram; if all sides are also equal it is a rhombus; one pair of parallel sides makes a trapezoid (isosceles only if the non-parallel sides are equal); and equal sides with right angles make a square.
You'll be able to
- identify parallelograms, rhombi, trapezoids and squares from their sides and angles.
- choose the most specific name for a quadrilateral.
- tell an isosceles trapezoid from a trapezoid.
Key words
- parallelogram
- A quadrilateral with two pairs of parallel sides.
- rhombus
- A parallelogram with all four sides equal.
- trapezoid
- A quadrilateral with one pair of parallel sides.
- isosceles trapezoid
- A trapezoid whose two non-parallel sides are the same length.
- square
- A rhombus whose sides meet at right angles.
Transcript
What is the type of this quadrilateral? Be as specific as possible with the given data. So it clearly is a quadrilateral. We have four sides here. And we see that we have two pairs of parallel sides. Or we could also say there are two pairs of congruent sides here as well.
This side is parallel and congruent to this side. This side is parallel and congruent to that side. So we're dealing with a parallelogram. Let's do more of these. So here it looks like a same type of scenario we just saw in the last one. We have two pairs of parallel and congruent sides, but all the sides aren't equal to each other.
If they're all equal to each other, we'd be dealing with a rhombus. But here, they're not all equal to each other. This side is congruent to the side opposite. This side is congruent to the side opposite. That's another parallelogram. Now this is interesting. We have two pairs of sides that are parallel to each other, but now all the sides have an equal length.
So this would be a parallelogram. And it is a parallelogram, but they're saying to be as specific as possible with the given data. So saying it's a rhombus would be more specific than saying it's a parallelogram. This does satisfy the constraints for being a parallelogram, but saying it's a rhombus tells us even more.
Not every parallelogram is a rhombus, but every rhombus is a parallelogram. Here, they have the sides are parallel to the side opposite and all of the sides are equal. Let's do a few more of these. What is the type of this quadrilateral? Be as specific as possible with the given data .
So we have two pairs of sides that are parallel, or I should say one pair. We have a pair of sides that are parallel. And then we have another pair of sides that are not. So this is a trapezoid. But then they have two choices here. They have trapezoid and isosceles trapezoid.
Now an isosceles trapezoid is a trapezoid where the two non-parallel sides have the same length, just like an isosceles triangle, you have two sides have the same length. Well we could see these two non-parallel sides do not have the same length. So this is not an isosceles trapezoid.
If they did have the same length, then we would pick that because that would be more specific than just trapezoid. But this case right over here, this is just a trapezoid. Let's do one more of these. What is the type of this quadrilateral? Well we could say it's a parallelogram because all of the sides are parallel.
But if we wanted to be more specific, you could also see that all the sides are the same. So you could say it's a rhombus, but you could get even more specific than that. You notice that all the sides are intersecting at right angles. So this is-- if we wanted to be as specific as possible-- this is a square.
Let me check the answer. Got it right.
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