Answer:
125.6 cm²
Step-by-step explanation:
The circumference is 2πr, i.e., 2*3.14*4
The area will be 5cm times the circumference, i.e., 5*2*3.14*4 = 125.6
Assuming the top and bottom should not be added.
1) 8.5x10^8
2) 5.3x10^-3
3) 9.95x10^12
Since they have the same exponents, you just add or subtract and leave the rest the same.
