Proving a Quadrilateral Is an Isosceles Trapezoid

$70^{\circ}, 110^{\circ}, 70^{\circ}, 110^{\circ}$

$65^{\circ}, 85^{\circ}, 95^{\circ}, 115^{\circ}$

$40^{\circ}, 120^{\circ}, 130^{\circ}, 50^{\circ}$

$60^{\circ}, 90^{\circ}, 90^{\circ}, 60^{\circ}$