Answer:
There are 4 set of vertical angles.
Explanation:
The angles which are opposite by two traversal are called vertical angles.Vertically opposite angles are equal.
From the figure we can see that, a and b are two parallel lines and a traversal is given.
List of vertical angles.
1). < 1 and < 4 [<1 = <4]
2). <2 and <3 [ <2 = <3]
3). <5 and <8 [<5 = <8]
4). <6 and <7 [<6 = <7]