The answer is 6.33 units.
<h3>Problem Solution</h3>
Assuming the spool is a cylinder and the circumference we're winding around is that of a circle with the given area, we can write the relation between circumference and area as
... C = 2√(πA)
10 times the circumference is then
... 10C = 20√(π·20 cm²) = 40√(5π) cm ≈ 159 cm
<h3>Formula Derivation</h3>
The usual formulas for circumference and area are
... C = 2πr
... A = πr²
If we multiply the area formula by π and take the square root, we get
... πA = (πr)²
... √(πA) = πr
Multiplying this by 2 gives circumference.
... C = 2√(πA) = 2πr
Answer: Option 1
<u>Step-by-step explanation:</u>

Option 1 has a greater area than option 2.
2. He can break his strand of 10 blocks into 3 3 times 4. I think it is 74 blocks are needed.
Answer:
C.
Step-by-step explanation:
Multiply both sides by 15, which gives you r≥-75
Since the graph has to go in the direction of numbers greater than -75, that would be -74, -73, -72, etc. So, it is C.