Answer:
40. Alternate exterior angles.
41.
.
42.

43.

Explanation:
Given:
From the figure, l and m are 2 lines and p and n are the transversals on the 2 lines.
Question 40:
[tex]m\angle 10\textrm{ and }m\angle 6[/tex] lie exterior to lines l and m are also alternate to each other. Therefore, they are called as a pair of alternate exterior angles.
Question 41:
If lines l || m, then the angles
are a pair of supplementary angles.
Therefore, the sum of angles 2 and 3 is equal to 180.

Therefore,
.
Question 42:
If lines l || m, then the angles
are a pair of alternate interior angles and equal to each other.
Therefore,


Therefore,
.
Question 43:
If lines l || m, then the angles
are a pair of alternate exterior angles and equal to each other.
Therefore,


Therefore,
.