Chapter Review
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Recall the classification of quadrilaterals. You can begin by finding the slopes of the sides.
Isosceles trapezoid
Let's plot the given points on a coordinate plane and graph the quadrilateral.
To determine the most precise name for our quadrilateral, let's 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, let's find the slopes of the sides using the Slope Formula.
| Side | Slope Formula | Simplified |
|---|---|---|
| Slope of HA: ( - 9,10), ( 2,10) | 10- 10/2-( - 9) | 0 |
| Slope of AT: ( 2,10), ( 4, 4) | 4- 10/4- 2 | - 3 |
| Slope of TW: ( 4, 4), ( - 11, 4) | 4- 4/-11- 4 | 0 |
| Slope of WH: ( - 11, 4), ( - 9,10) | 10- 4/- 9-( - 11) | 3 |
We can tell that the quadrilateral has exactly one pair of parallel sides. Therefore, it is either a trapezoid or an isosceles trapezoid. To check, we can find the lengths of the legs of the trapezoid using the Distance Formula.
| Side | Distance Formula | Simplified |
|---|---|---|
| Length of AT: ( 2,10), ( 4, 4) | sqrt(( 4- 2)^2+( 4- 10)^2) | sqrt(40) |
| Length of WH: ( - 11, 4), ( - 9,10) | sqrt(( - 9-( - 11))^2+( 10- 4)^2) | sqrt(40) |
The legs of our trapezoid are congruent. Therefore, the most precise name for this quadrilateral is an isosceles trapezoid.