## Elementary Geometry for College Students (6th Edition)

Similar figures have congruent corresponding angles. Thus... $m\angle A=m\angle H=70^{\circ}$ $m\angle K=70^{\circ}$ $m\angle B=m\angle J=110^{\circ}$ The interior angles of a quadrilateral will sum to $360^{\circ}$. $360-70-70-110=110$ $m\angle L=110^{\circ}$ A quadrilateral with two sets of congruent opposite angles is a parallelogram. Therefore, quadrilateral HJKL is a parallelogram. Since both quadrilaterals are similar, quadrilateral ABCD is also a parallelogram.