From the figure we notice that the triangle given is an equilateral one. Then all of its angles are equal. Now, we know that the sum of interior angles in a triangle is equal to 180°, as we mentioned before in this case all the angles are equal, then we have:
[tex]3(8y+4)=180[/tex]Solving for y we have:
[tex]\begin{gathered} 3(8y+4)=180 \\ 24y+12=180 \\ 24y=180-12 \\ 24y=168 \\ y=\frac{168}{24} \\ y=7 \end{gathered}[/tex]Therefore y=7
