Explanation is in the file
tinyurl.com/wpazsebu
The formula for sector area is simple - multiply the central angle by the radius squared, and divide by 2: Sector Area = r² * α / 2.
now, bear in mind that all these ones are lines, and to graph a line all you need is two points, so let's pick a couple of random values for say "x" and let's see what we get for "y" and that's our x,y point.
3)
![9x+4y=-16\implies \stackrel{\textit{using x = 0}~\hfill }{9(0)+4y=-16}\implies 4y=-16 \\\\\\ y=\cfrac{-16}{4}\implies y=-4~\hspace{10em}(0~~,~~-4) \\\\[-0.35em] ~\dotfill\\\\ 9x+4y=-16\implies \stackrel{\textit{using x = -4}~\hfill }{9(-4)+4y=-16}\implies -36+4y=-16 \\\\\\ 4y=20\implies y = \cfrac{20}{4}\implies y = 5~\hspace{10em}(-4~~,~~5)](https://tex.z-dn.net/?f=9x%2B4y%3D-16%5Cimplies%20%5Cstackrel%7B%5Ctextit%7Busing%20x%20%3D%200%7D~%5Chfill%20%7D%7B9%280%29%2B4y%3D-16%7D%5Cimplies%204y%3D-16%20%5C%5C%5C%5C%5C%5C%20y%3D%5Ccfrac%7B-16%7D%7B4%7D%5Cimplies%20y%3D-4~%5Chspace%7B10em%7D%280~~%2C~~-4%29%20%5C%5C%5C%5C%5B-0.35em%5D%20~%5Cdotfill%5C%5C%5C%5C%209x%2B4y%3D-16%5Cimplies%20%5Cstackrel%7B%5Ctextit%7Busing%20x%20%3D%20-4%7D~%5Chfill%20%7D%7B9%28-4%29%2B4y%3D-16%7D%5Cimplies%20-36%2B4y%3D-16%20%5C%5C%5C%5C%5C%5C%204y%3D20%5Cimplies%20y%20%3D%20%5Ccfrac%7B20%7D%7B4%7D%5Cimplies%20y%20%3D%205~%5Chspace%7B10em%7D%28-4~~%2C~~5%29)
check the red line in the picture below.
4)

check the blue line in the picture below.
46 feet tall is how tall the new drawing is.
Supplementary angles sum to 180 degrees.
So if one angle is 20 degree more than the other...
x+(x+20)=180
2x+20=180
2x=160
x=80
x+20=100
answer: 80° and 100°