## Elementary Geometry for College Students (7th Edition)

$m\angle K=79^{\circ}$
Since the two quadrilaterals are similar, the corresponding angles are congruent. So... $m\angle H=m\angle A=55^{\circ}$ $m\angle J=128^{\circ}$ $m\angle D=m\angle L=98^{\circ}$ The four interior angles of a quadrilateral sum to $360^{\circ}$. $360-55-128-98=79$ $m\angle K=79^{\circ}$