Determine whether quadrilateral ABCD with vertices A(-4,-5), B(-3,0), C(0, 2), and D(5, 1) is a trapezoid,
Step 1: Find the slope of AB. The slope ofAB is
Step 2: Find the slope of DC. The slope of DC is
v
Step 3: Find the slope of BC. of The slope of BC is
Step 4: Find the slope of AD. The slope AD is
The quadrilateral is
trapezoid because

9514 1404 393

  ABCD is a trapezoid. The bases are BC and AD.

Step-by-step explanation:

I don't care for the tedium of entering the same numbers into a calculator over and over. So, I prefer to let a spreadsheet or graphing calculator compute the slope formula for these points. The results are shown in the attachment.

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1. Slope of AB = 5

2. Slope of DC = -0.2 . . . . . perpendicular to AB

3. Slope of BC = 2/3

4. Slope of AD = 2/3 . . . . . parallel to BC

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The quadrilateral is a trapezoid because it has one pair of parallel sides.

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The slope formula is ...

  m = (y2 -y1)/(x2 -x1)

In the spreadsheet, the (x2, y2) values are taken from the next line down. That is why point A is repeated at the bottom--so there is something to compute with.