That would be 5, all you need to do is divide by 2 or mltiply by 0.5 to get half of a number
I used Desmos to graph it but here are the coordinates used to graph it in the pictures below.
I only (sort of) know 3 and 4
3. Andle 1 is an example of an angle bigger than

I don't know what you call it.
4. If you have a straight line, both angles (or more) added up need to be

so if angle 1 is 129, 180-129=51
angle 2 is

If 1 is what is the relationship between the two angles, then maybe the answer is that they both added up need to be 180 degress (?)
And 2 is probably the same as 3 but with angle 2, angle two is an example of an angle smaller than 90 degrees
To find the slope given two points, you need to subtract the two y values over the two x values
(-5,-3) (9,-6)
-5 will be x1, and -3 will be y1. 9 will be x2, and -6 will be y2. You then need to put the numbers in the correct place in the equation.
y2-y1 -6-(-3) -9
-------- = -------- = ----
x2-x1 9-(-5) 14
Now that we have the slope (-9/14) you can use one of the coordinates to find the value of b.
Let's use (9,-6).
-6=-9/14(9)+b
-6=-81/14+b
+81/14
b=-3/14
Your final equation is y=-9/15x-3/14