Angle 1 = 180-10= 170 degrees, and the relationship is called supplementary angles
Here is your answer:
6.78 rounded to the nearest tenth = 7.00 because the 7 in 6.78 is greater then five.
8.21 rounded to the nearest tenth= 8.00 because the 2 in 8.21 is NOT greater than five.
How to get answer by Mimiwhatsup:

2:3
it was originally 8:12, but it has to be simplified. 2/3 can also work as an answer.
Answer:
it will compare unit to some quanlity to a different number of units of a different queality.
Step-by-step explanation:
a/b=c/d proportions are two fractions that are equal example: 1/2=2/4