In a circle, the internal vertical angles have a formula of [tex] \frac{a + b}{2} [/tex]
In this case, the formula would be: [tex] \frac{4x + 2x}{2} = \frac{6x}{2} = 3x[/tex]
We know that whole circle is 12x. And 12x is equal to 360°. When we put that into equation: [tex]12x = 360 [/tex]
[tex]x = 30[/tex]
If x is 30°: [tex]3x =3 \times 30 = 90[/tex]
So, angle 7 is 90°.
