13. A side of the triangle below has been extended to for an exterior angle of 161°. Find the value of x.
D. 19°
E. 46°
F. 134°
Since the exterior angle of a triangle is equal to the sum of the two interior opposite angles, we can find the value of x by subtracting 161° from 180° (since the sum of the two interior opposite angles is equal to 180°):
x = 180° - 161° = 19°
So, the value of x is 19°.
Answer: D. 19°