Sum of the interior angles of any triangles equalls to 180 degrees thus :
[tex]36 + 4s + 2s = 180[/tex]
Collect like terms :
[tex]6s + 36 = 180[/tex]
Subtract both sides 36
[tex]6s + 36 - 36 = 180 - 36[/tex]
[tex]6s = 144[/tex]
Divide both sides by 6
[tex] \frac{6s}{6} = \frac{144}{6} \\ [/tex]
[tex]s = 24[/tex]
