The measures of all of the interior angles of the triangle are 70 degrees, 70 degrees and 40 degrees
Solution:
Given that exterior angle of triangle is 140 degrees
The exterior angle of a triangle is equal to the sum of the measures of the two non-adjacent interior angles
Given that adjacent angles are congruent
Let one of the non adjacent interior angles be "x"
x + x = 140
2x = 140
x = 70
So the two interior angles are 70 degrees and 70 degrees
Let us find the third interior angle
The angle sum property of a triangle states that the interior angles of a triangle always add up to 180 degrees
70 + 70 + third angle = 180
third angle = 180 - 70 - 70
third angle = 180 - 140
third angle = 40 degrees
Thus the measures of all of the interior angles of the triangle are 70 degrees, 70 degrees and 40 degrees
