Let's solve
in ∆GNK
Apply pythagorean theorem
[tex]\\ \sf\longmapsto NK^2=GN^2-GK^2=130^2-47^2=16900-2209=14691[/tex]
[tex]\\ \sf\longmapsto NK=\sqrt{14691}[/tex]
[tex]\\ \sf\longmapsto NK=121(Approx)[/tex]
If you observe the traingle
[tex]\\ \sf\longmapsto LJ^2=JN^2-LN^2[/tex]
[tex]\\ \sf\longmapsto LJ^2=130^2-78^2[/tex]
[tex]\\ \sf\longmapsto LJ^2=16900-6084[/tex]
[tex]\\ \sf\longmapsto LJ^2=10816[/tex]
[tex]\\ \sf\longmapsto LJ=\sqrt{10816}[/tex]
[tex]\\ \sf\longmapsto LJ=104[/tex]
So
in ∆HNL
[tex]\\ \sf\longmapsto HN^2=104^2+78^2[/tex]
[tex]\\ \sf\longmapsto HN^2=10816+6084[/tex]
[tex]\\ \sf\longmapsto HN^2=16900[/tex]
[tex]\\ \sf\longmapsto HN=\sqrt{16900}[/tex]
[tex]\\ \sf\longmapsto HN=130[/tex]
Done .