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- [Voiceover] Rectangle ABCD is graphed
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in the coordinate plane.
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The following are the
vertices of the rectangle,
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and they give us the labels
for the vertices as well.
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Given these coordinates,
what is the length
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of side AD of this rectangle?
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So let's just plot it.
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That's one way that we could tackle it.
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So let's, let me see,
all of these are actually
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in the first coordinate,
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so I could focus on the first coordinate.
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So let's say that's my y-axis.
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It's my y-axis, and let me draw my x-axis.
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My x-axis, and actually
I wanna really focus in
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on the points A and D,
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because we just need to
find the length of the side
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from point A to point D.
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So point A, let me do
this in another color.
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So point A is at x equals seven,
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y is equal to one.
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So one, two, three, four,
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five, six, seven, so
that's x equals seven.
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Y is equal to one.
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Y is equal to one, so that
is point A right over there.
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Point A, let me label it. Point A.
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And then where's point D?
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Point D has the exact same x-coordinate,
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but its y-coordinate
is a little bit higher.
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Its y-coordinate is six.
It's actually five higher.
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So point D is at x equals seven,
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y is equal to six.
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So y is equal to one, two, three,
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four, five, and six.
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So that's y is equal to six,
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and so we can draw the point.
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It is going to be right over here.
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This is point D,
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and we could actually connect
them with a line, if we like,
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to show that this is
a side of a rectangle.
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Let me draw that. I can
just draw this like this.
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And there you have it.
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I haven't even drawn
the whole rectangle yet,
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but just by plotting these two points,
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we can think about how long side AD is.
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We could say, look, the x
doesn't change going from A to D,
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but we do increase in
the y direction by five.
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We go from y is equal to
one to y is equal to five,
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to y is equal to six.
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So our change in y is equal to five.
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So what's the length of this line?
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Well, it's gonna be five.
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It's gonna be five,
whatever the units are.
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So that's the length of side AD.
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It's going to be equal to five.
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We went from the point (7, 1)
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to the point (7, 6).
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Now, they said that this was a rectangle.
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Now, just for our satisfaction,
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we can draw the entire rectangle.
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We have that point B
that is at x equals five,
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y is equal to one, so let me draw that.
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And I'm just doing this just
for fun now at this point.
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We're done with the problem.
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So x equals five, y equals
one. That's right over here.
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That's point B.
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Let me write B. That's the point (5, 1).
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And then we have the point C.
I'll do this in another color.
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The point C is at x
equals five, y equals six.
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X equals five, y equals six.
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Point C is right over here.
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Point C is the point x equals
five, y is equal to six.
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And then we could connect
all the dots, if we like,
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and clearly see that it is a rectangle.
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So I could connect those.
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I could connect these two.
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Then I could connect these two.
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And then we see that we
indeed have a rectangle.
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But we answered it awhile
ago that the length
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of side AD is equal to five.
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If we cared about the other sides,
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the length of BA, well, this is two.
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a difference of two along the x direction,
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the horizontal direction,
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difference of two along the x direction,
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difference of five in the y direction.
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We go from y equals one to y equals six.
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So there you have it.
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We actually will figure
out all of the dimensions
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of this rectangle.