Please help with a math problem. Please explain how you got the 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.

∠acb = 8°

step-by-step explanation:

∠xba lies on the circle and is half the measure of the intercepted arc ax

hence

measure of arc ax = 2 × 42° = 84°

∠acb is outside the circle and is

∠acb = (arcab - arcax ), hence

∠acb = 0.5 (100 - 84) = 0.5 × 16° = 8°

i dont get the question

step-by-step explanation: