Chapter Test
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Recall the classification of quadrilaterals. We can begin by finding the slopes of the sides.
trapezoid
Let's plot the given points on a coordinate plane and graph the quadrilateral.
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, let's find the slopes of the sides using the Slope Formula.
Side | Slope Formula | Simplified |
---|---|---|
Slope of AB: ( 1,2), ( 11,2) | 2- 2/11- 1 | 0 |
Slope of BC: ( 11,2), ( 7,5) | 5- 2/7- 11 | - 3/4 |
Slope of CD: ( 7, 5), ( 4,5) | 5- 5/4- 7 | 0 |
Slope of DA: ( 4,5), ( 1,2) | 2- 5/1- 4 | 1 |
We can tell that the slopes of two opposite sides of our quadrilateral are equal. Therefore, the pair of opposite sides are parallel and the quadrilateral is either a trapezoid or an isosceles trapezoid. To check, we can find the lengths of its legs using the Distance Formula.
Side | Distance Formula | Simplified |
---|---|---|
Length of AD: ( 1,2), ( 4,5) | sqrt(( 4- 1)^2+( 5- 2)^2) | sqrt(18) |
Length of BC: ( 11,2), ( 7, 5) | sqrt(( 7- 11)^2+( 5- 2)^2) | sqrt(25) |
The legs of the trapezoid are different lengths, so the most precise name for this quadrilateral is a trapezoid.