Answer: 140
Step-by-step explanation:
The measure of the other arc, say y, enclosed by the two secants can be found by:
[tex]\frac{1}{2}(30^{\circ}-y^{\circ})=10^{\circ}\\30^{\circ}-y^{\circ}=20^{\circ}\\y=10^{\circ}[/tex]
So the measure of the 30-degree arc, y, and X is 180 degrees (since it's half of the circumference). This means X = 180 - 30 - 10 = 140.
