Answer:
===============
Given
- Two parallel lines,
- Included triangle between the parallel lines,
- Two interior angles of the triangle are m and n,
- Another angle of 40°.
To find
- The sum of angles m and n
Solution
As per given, the missing interior angle is corresponding with 40° angle.
Since corresponding angles are equal, the third interior angle of the triangle is 40°.
Sum of three interior angles is 180°:
- m + n + 40 = 180
- m + n = 180 - 40
- m + n = 140
