The answer to solve these problems is that the full circle is 360 degrees, the way to find the answer is to have to equal sides that equal 360 degrees. That means one half of 360 degrees is 180 degrees. Hope this helps.
Answer:

Step-by-step explanation:
Diameter = 12
Radius = 12/2 = 6


Answer:
9000
Step-by-step explanation:
3437 rounds to 3000 and 6391 rounds to 6000 add them
380-57= 323
Answer: 323 legos remain