Two angles are supplementary if their sum is 180 degrees.
Here we are given:
Angle GHI measures (28x + 40)° and angle JHI measures (7x)°.
Sum of angle GHI and JHI is 180.



dividing both sides by 35,
x=4
Now let us find angle JHI
angle JHI = 7x = 7*4 =28
Answer : Angle JHI is 28 degrees.