I think it is acute because below 90 is acute above 90 is obtuse and exactly 90 is right
The answer is 4.953 I don't understand how you would use a table sorry.
The longest angle would be across from the one with the longest side. In this case it would be across from DF
What the maning of that ?
Answer:

Step-by-step explanation:
When you not given the vertex form, the you are given the standard form:

The value of k, is the y-value of the vertex of the function.
To find the value of k, you plug in

In order works, you evaluate

This will give you the k-value