<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:
12.5 pie , 39.25 using pie=3.14, and 39.28 to be exact
Step-by-step explanation:
BTW n=pie
10in= Diameter
5in=Radius
Area=n5^2
= 25n/2
=12.5n
12.5 times 3.14= 39.25
22/7 times 12.5= 39.2857143
I'll help you with #7, and hopefully then you will be able to do #8 on your own. the formula for the volume of a pyramid and cone is the area of the base times the height of the figure divided by three. knowing this, we must first find the area of the base. since it is a square, we need to multiply the length times the width. (6 • 6 = 36) then you multiply that times the height of the figure (36 • 4 = 144) finally, we need to divide that by three (144 divide by three is 48.) so the answer is b. hope this helped :$
Answer:
C) 
Step-by-step explanation:
Remember to use the change of base formula, which states that 
so that everything has the same base of 10
