McGraw Hill Integrated II, 2012
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McGraw Hill Integrated II, 2012 View details
Study Guide and Review
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Exercise 39 Page 534

Begin by finding the slopes of the sides.

Type of Quadrilateral: Rhombus, rectangle, and square.
Explanation: See solution.

Practice makes perfect

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

To list all the names that apply for our parallelogram, let's recall the definitions of rhombus, rectangle and square.
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.

Slope Formula: y_2-y_1/x_2-x_1
Side Endpoints Substitute Simplify
QR Q( 12,0) and R( 6,- 6) - 6- 0/6- 12 1
RS R( 6,- 6) and S( 0,0) 0-( - 6)/0- 6 - 1
ST S( 0,0) and T( 6,6) 6- 0/6- 0 1
TQ T( 6,6) and Q( 12,0) 0- 6/12- 6 - 1

We can tell that the consecutive sides are perpendicular, as their slopes are opposite reciprocals. 1 ( - 1 ) = -1 Therefore, our parallelogram is a rectangle. To check if it is a rhombus and square, we can find the lengths of its sides using the Distance Formula.

Distance Formula: sqrt((x_2-x_1)^2+(y_2-y_1)^2)
Side Endpoints Substitute Simplify
QR Q( 12,0) and R( 6,- 6) sqrt(( 6- 12)^2+( - 6- 0)^2) 6sqrt(2)
RS R( 6,- 6) and S( 0, 0) sqrt(( 0- 6)^2+( 0-( - 6))^2) 6sqrt(2)
ST S( 0, 0) and T( 6, 6) sqrt(( 6- 0)^2+( 6- 0)^2) 6sqrt(2)
TQ T( 6,6) and Q( 12,0) sqrt(( 12- 6)^2 + ( 0- 6)^2) 6sqrt(2)

Our parallelogram has four congruent sides. Therefore, it is a rhombus, a rectangle and a square.