McGraw Hill Integrated II, 2012
MH
McGraw Hill Integrated II, 2012 View details
6. Trapezoids and Kites
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Exercise 79 Page 530

Graph:

Is It a Rectangle? No, see solution.

Practice makes perfect

Let's plot the given points and draw the quadrilateral on a coordinate plane.

We can use the Slope Formula to determine whether the figure is a rectangle. Let's find the slope of each side.

Side Slope Formula Simplify
Slope of JK, ( 0,7), ( - 8,6) 6- 7/- 8- 0 1/8
Slope of KL, ( - 8,6), ( - 7, 0) 0- 6/- 7-( - 8) - 6
Slope of LM, ( - 7, 0), ( 1, 1) 1- 0/1-( -7) 1/8
Slope of MJ, ( 1,1), ( 0,7) 7- 1/0- 1 - 6

The slopes of opposite sides are equal. This means we have two pairs of parallel sides. Therefore, we know that the quadrilateral is in fact a parallelogram. However, we can also tell that consecutive sides are not perpendicular, because their slopes are not opposite reciprocals. - 6 * 1/8 ≠ -1 Therefore, our quadrilateral is not a rectangle, as it does not have four right angles.