Answer:
Value of x = 20°
Angle B = 60°
Exterior angle to B = 300°
Explanation:
Given:
Angles of triangle.
A = 2x
B = 3x
C = 4x
We know that,
A + B + C = 180°
2x + 3x + 4x = 180°
9x = 180°
x = 20°
Value of x = 20°
Angle B = 3x
Angle B = 3(20°)
Angle B = 60°
Exterior angle to B = 360° - 60°
Exterior angle to B = 300°