Since triangle GHI is similar to triangle LKJ (denoted as \( \triangle GHI \sim \triangle LKJ \)), the corresponding angles in the two triangles are equal.
Given:
- \( m\angle G = 30^\circ \)
- \( m\angle H = 80^\circ \)
- \( m\angle I = 70^\circ \)
According to the property of similar triangles:
- \( m\angle L = m\angle G = 30^\circ \)
- \( m\angle K = m\angle H = 80^\circ \)
- \( m\angle J = m\angle I = 70^\circ \)
Thus, the measurements of angles L, K, and J are:
- \( m\angle L = 30^\circ \)
- \( m\angle K = 80^\circ \)
- \( m\angle J = 70^\circ \)