Hey there!
ANSWER: <u>vertex</u>
<h2>
EXPLANATION:</h2>
Fill in the blank:
The endpoint is the <u>vertex</u> of the angle.
This is your answer because an angle is formed by two rays which are the sides of an angle and they have an endpoint called the vertex.
Hope this helps!

Answer:
1.
is a perfect square trinomial
Step-by-step explanation:
2. Perfect square trinomials are algebraic expressions with three terms that are created by multiplying a binomial to itself.
3. I will upload a picture showing my work