Answer:
Part 1) The area of the circle is 
Part 2) The circumference of the circle is 
Step-by-step explanation:
step 1
The area of a circle is equal to

we have
---> the radius is half the diameter

substitute


step 2
The circumference of a circle is equal to

we have

substitute


Answer:
Please see the attached pictures for full solution.
Answer:
3400
Step-by-step explanation:
60 * 70 = 4200
70 - 10 - 20 = 40
20 * 40 = 800
4200 - 800 = 3400
Answer:
b
Step-by-step explanation: