Question

use the figure to name the vertex of ∠1.
options:
a) c
b) a
c) d

Explanation:

Step1: Recall vertex definition

A vertex of an angle is the common endpoint of the two rays forming the angle.

Step2: Identify ∠1's rays

For ∠1, the two rays meet at point A. So the vertex is A.

Answer:

B) A