Answer:
28
Step-by-step explanation:
18+6+4=28
Answer:
5=3+2
7=5+2
9=7+2
so this is 3,5,7,9
Step-by-step explanation:
For every 3 squares there are 2 circles
Astronomers deal with objects in space, so it's most likely they would use geometry to determine how far they are, how big they are, etc.
Have a nice day! :)