Answer:
Their sum is 140. The measure of an exterior angle is supplementary to the respective interior angle.
Step-by-step explanation:
Since the angle are on a straight line, m2 and 140 sum to 180.
So m2=40. Because a triangle has 180 degrees, m1 and m3 must sum to 140.
The exterior angle is always on the same incline as the interior angle, so it is always supplementary to the interior angle.
Line CA is a straight line, meaning it adds up to 180°
Line BE splits the line into two supplementary angles, because when the two angles are added together they will equal 180°
Using the rule of supplementary angles, we can then make the equation 3x + 8x + 15 = 180
Now, simplify the equation by combining like terms
11x + 15 = 180
To solve, isolate x
11x + 15 = 180
11x = 165
x = 15