6. Trapezoids and Kites
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A trapezoid is isosceles if its non-parallel sides are congruent.
ABCD is an isosceles trapezoid.
In the previous exercise we already found that ABCD is a trapezoid. A trapezoid is isosceles if its non-parallel sides are congruent. Therefore, we want to check whether the lengths of AB and CD are equal. To do this, we will use the Distance Formula.
| Side | Distance Formula | Simplified |
|---|---|---|
| Length of AB: ( -4,-1), ( -2,3) | sqrt(( -2-( -4))^2+( 3-( -1))^2) | sqrt(20) |
| Length of CD: (3,3), (5, - 1) | sqrt((5-3)^2+(-1-3)^2) | sqrt(20) |
Since the lengths are equal, legs AB and CD are not congruent. Therefore, trapezoid ABCD is isosceles.