Answer: [tex]7,5.66,39^{\circ}[/tex]
Step-by-step explanation:
Given
[tex]IJ=9\\\angle I=51^{\circ}[/tex]
from figure, we can write
[tex]\Rightarrow \sin 51^{\circ}=\dfrac{HJ}{9}\\\\\Rightarrow HJ=9\sin 51^{\circ}=6.99\approx 7[/tex]
[tex]\Rightarrow \cos 51^{\circ}=\dfrac{HI}{9}\\\Rightarrow HI=9\cos 51^{\circ}\\\Rightarrow HI=5.66[/tex]
In right angle trianle, the sum of the remaining two angles is [tex]90^{\circ}[/tex]
[tex]\therefore 51^{\circ}+\angle J=90^{\circ}\\\Rightarrow \angle J=90^{\circ}-51^{\circ}\\\Rightarrow \angle J=39^{\circ}[/tex]