Answer:
[tex]20^{\circ}[/tex]
Step-by-step explanation:
We can see here that the two unknown angles are on the straight line . So its measure will be 180° .
[tex]\implies (4x + 20^{\circ})+(x-15^{\circ}) = 180^{\circ} \\\\\implies 5x + 5^{\circ} = 180^{\circ} \\\\\implies 5x = 175^{\circ} \\\\\implies x =\dfrac{175^{\circ}}{5}\\\\\implies x = 35^{\circ} [/tex]
Now the angle F and the angle (x-15)° are vertically opposite angles . So they will be equal .
[tex]\implies x - 15^{\circ} \\\\\implies 35^{\circ} - 15^{\circ} \\\\\implies \boxed{ 20^{\circ} } [/tex]
