Pearson Geometry Common Core, 2011
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Pearson Geometry Common Core, 2011 View details
7. Polygons in the Coordinate Plane
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Exercise 23 Page 404

Recall the classification of quadrilaterals. You can begin by finding the slopes of the sides.

Kite

Practice makes perfect

We will plot the given points on a coordinate plane and graph the quadrilateral.

To determine the most precise name for our quadrilateral, we will review the classification of quadrilaterals.
Quadrilateral Definition
Parallelogram Both pairs of opposite sides are parallel
Rhombus Parallelogram with four congruent sides
Rectangle Parallelogram with four right angles
Square Parallelogram with four congruent sides and four right angles
Trapezoid Quadrilateral with exactly one pair of parallel sides
Isosceles Trapezoid Trapezoid with legs that are congruent
Kite Quadrilateral with two pairs of consecutive sides congruent and no opposite sides congruent

Now, we will find the slopes of the sides using the Slope Formula.

Side Slope Formula Simplified
Slope of FG: ( 0,0), ( 5,5) 5- 0/5- 0 1
Slope of GH: ( 5,5), ( 8, 4) 4- 5/8- 5 - 1/3
Slope of HI: ( 8, 4), ( 7, 1) 1- 4/7- 8 3
Slope of IF: ( 7, 1), ( 0,0) 0- 1/0- 7 1/7

We can tell that the slopes of the opposite sides of our quadrilateral are not equal. Therefore, both pairs of opposite sides are not parallel and our quadrilateral can be a kite. To check, we can find the lengths of its sides using the Distance Formula.

Side Distance Formula Simplified
Length of FG: ( 0,0), ( 5,5) sqrt(( 5- 0)^2+( 5- 0)^2) sqrt(50)
Length of GH: ( 5,5), ( 8, 4) sqrt(( 8- 5)^2+( 4- 5)^2) sqrt(10)
Length of HI: ( 8,4), ( 7, 1) sqrt(( 7- 8)^2+( 1- 4)^2) sqrt(10)
Length of IF: ( 7, 1), ( 0,0) sqrt(( 0- 7)^2+( 0- 1)^2) sqrt(50)

Our quadrilateral has two congruent pairs of consecutive sides, and its opposite sides are not congruent. Therefore, the most precise name for this quadrilateral is kite.