Interior angles of a parallelogram have opposite angles identified as "a" and "b".
angles K and I are "a"
angles H and J are "b"
"a" and "b" are supplementary angles, they sum up to 180°.
Angle J is supplementary angle of angle K. Its measure is 143°.
180° - 37° = 143°
Angle H is also 143° while angle I is 37°
