Find the proportion.
test is worth 50 points; test score of 84%

So if the test is worth 50 points and you got 84% on it you would get 50 times 84/100 points

so 50/1 times 84/100=(50*84)/(50*2)
this is also (50/50) times (84/2)
so you can take out the 50/50 which equals 1 and get 84/2 which divides to equal 42
so you will get 42 points

If we know that 
50points ---------- 100%
x is ----------------- 84%
Know we can write
x*100%=50*84%      /:100%

- its the result

One unique triangle, because those angles add up to 180, and that's how many degrees there are in one triangle.