In figure, if \overline{ABC} is a straight line , then x =

×
50

×
60

✓
70

×
80

×
90
In figure, if \overline{ABC} is a straight line , then x =
50
60
70
80
90
For a triangle, an exterior angle of a triangle is equal to the sum of its two opposite nonadjacent interior angles.
In figure,
130\degree = x +(x10 )
Therfore,
x = 70\degree