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Proving Trapezoids

Graph Quadrilateral ABCD with vertices A(-2,1), B(3,3), C(5,1), and D(-5,-3)

What evidence do you have that this is or isn't a parallelogram? What evidence do you have that this is or isn't a trapezoid?

Graph Quadrilateral ABCD with vertices A(-2,3), B(1,2), C(2,0), and D(-4,2)

What evidence do you have that this is or isn't a trapezoid? What evidence do you have that this is or isn't an isosceles trapezoid?

Check all of the angles on BOTH graphs above. What patterns do you notice?