In which diagram are angles 1 and 2 vertical angles?
Vertical angles are a pair of non-adjacent angles formed by the intersection of two straight lines.
Answer: The angles shown in the first figure (a) are vertical angles.
Let us understand how to identify vertical angles which are also known as vertically opposite angles.
When two lines intersect, the angles formed opposite to each other are termed as vertical angles.
(a) In the first figure, ∠1 and ∠2 are not adjacent angles. So, ∠1 and ∠2 are vertical angles.
(b) In the second figure, ∠1 and ∠2 are adjacent angles. So, ∠1 and ∠2 are not vertical angles.
So, the pair of angles in the first figure (a) are vertical angles.