Answer:
The angle 1 ( ∠1 ) measure must be 105°
A is correct.
Explanation:
In the diagram, the measure of ∠3 is 105°
Please see the attachment for diagram.
In the diagram, we are given three line
Line 1 traversal of two line L2 and L3
∠3 for by Line 1 and Line 2
As we know when two line intersect form vertically opposite angle.
∠3=∠1 (Vertically Opposite angle Theorem)
But ∠3=105°
Thus, ∠1=105°
Hence, The angle 1 ( ∠1 ) measure must be 105°