JKLM is a triangle. Find the measure of m

We need x and y
JKLM is a rectangle not triangle
Opposite sides of rectangle are equal
Now
[tex]\\ \rm\Rrightarrow 4y+5=2y+35[/tex]
[tex]\\ \rm\Rrightarrow -2y=-30[/tex]
[tex]\\ \rm\Rrightarrow y=-30/-2[/tex]
[tex]\\ \rm\Rrightarrow y=15[/tex]
And
[tex]\\ \rm\Rrightarrow x+31=5x-9[/tex]
[tex]\\ \rm\Rrightarrow -4x=-40[/tex]
[tex]\\ \rm\Rrightarrow x=10[/tex]