Explanation:
By arc sum Postulate of a circle:
2 x + 3x + 4x = 360°
9x = 360°
x = 360°/9
x = 40°
3x = 3* 40° = 120°
By inscribed angle theorem:
By tangent secant theorem:
Since, measure of central angle is equal to the measure of its corresponding minor arc.
By angle sum Postulate of a triangle: