The sum of internal angles in a triangle is equal to 180 degrees. Therefore we need to sum all the angles and make it equal to 180 to determine the value of x. We have:
[tex]\begin{gathered} x+8x+90=180 \\ 9x+90=180 \\ 9x=180-90 \\ 9x=90 \\ x=\frac{90}{9}=10 \end{gathered}[/tex]With the value of x we can determine the value of the angles:
[tex]\begin{gathered} \text{angle}1\text{ = x=10 degrees } \\ \text{angle}2=8x=8\cdot10=80\text{ degrees} \end{gathered}[/tex]