McGraw Hill Integrated II, 2012
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McGraw Hill Integrated II, 2012 View details
5. Rhombi and Squares
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Exercise 6 Page 517

Recall the classification of quadrilaterals. Begin by finding the slopes of the sides.

Type of Parallelogram: Parallelogram, none of the mentioned.
Explanation: See solution.

Practice makes perfect

Let's plot the given points on a coordinate plane and graph the parallelogram.

To determine the most precise name for our parallelogram, let's review the classification of parallelograms.
Quadrilateral Definition
Rhombus Parallelogram with four congruent sides
Rectangle Parallelogram with four right angles
Square Parallelogram with four congruent sides and four right angles

Now, let's find the slopes of the sides using the Slope Formula.

Side Points y_2-y_1/x_2-x_1 Simplify
QR ( - 2,-1), ( - 1,2) 2-( -1)/- 1-( - 2) 3
RS ( - 1,2), ( 4,1) 1- 2/4-( - 1) - 1/5
ST ( 4,1), ( 3, -2) -2- 1/3- 4 3
TQ ( 3,- 2), ( - 2,- 1) -1-( -2)/- 2- 3 - 1/5

We can tell that consecutive sides are not perpendicular, as their slopes are not opposite reciprocals. 3 ( - 1/5 ) ≠ -1 Therefore, our quadrilateral is either a parallelogram or a rhombus. To check, we can find the lengths of its sides using the Distance Formula.

Side Points d = sqrt((x_2-x_1)^2 + (y_2-y_1)^2) Simplify
QR ( - 2,- 1), ( - 1,2) sqrt(( - 1-( - 2))^2+( 2-( -1))^2) sqrt(10)
RS ( - 1,2), ( 4, 1) sqrt(( 4-( - 1))^2+( 1- 2)^2) sqrt(26)
ST ( 4, 1), ( 3, -2) sqrt(( 3- 4)^2+( -2- 1)^2) sqrt(10)
TQ ( 3, -2), ( - 2,-1) sqrt(( - 2- 3)^2+( -1-( -2))^2) sqrt(26)

Our quadrilateral has two pairs of sides of different lengths. Therefore, the most precise name for this quadrilateral is a parallelogram, then it's none of the mentioned.