Answer:
28. 120 degrees
29. 30 degrees
30. 56 degrees & 124 degrees
31. 72 degrees, 108 degrees, and 18 degrees
Step-by-step explanation:
We assign variable x for the answer we are looking for (28-29).
28.
Supplement means x + y = 180 degrees. We also know x = 2y. Substitution gives us 3y = 180 degrees, so y = 60 degrees and x = 120 degrees.
29.
Complement means x + y = 90 degrees. We are given 2x = y. Substitution brings us 3x = 90 degrees, x = 30 degrees.
30.
Supplement means x + y = 180 degrees. We are told that y = 2x + 12, so we substitute. This gives 3x + 12 = 180 degrees, x = 56 degrees. Substituting that back into the equation for y, we get 124 degrees.
31.
Supplement means x + y = 180 degrees. Complement means x + z = 90 degrees. Using our given info, we know y = 6z. We can substitute that in to get x + 6z = 180. Subtracting our second and third equations, we get 5z = 90, z = 18 degrees. Therefore, x = 72 degrees, y = 108 degrees.
It is definitely J yes it is
Answer:
square kilometers
Step-by-step explanation:
The surface area of a sphere can be found using the formula
. Since the diameter is 3500 km then its radius is half of this. 3500 divided in two is 1,750 units. Substitute r=1,750.

The surface area of the moon is about 38,465,000 square kilometers. Write this is scientific notation using base. 
Ratio = 5:2:3:8
Sum of all internal angles = 360°
5x + 2x + 3x + 8x = 360°
18x = 360°
x = 20°
Therefore,
5x = 100°
2x = 40°
3x = 60°
8x = 160°
5:2:3:8 :: 100:40:60:160.