Answer:
Part 1) [tex]A=124.63\ in^{2}[/tex]
Part 2) Option b
Part 3) As n increases, ns get closer to [tex]2\pi r[/tex]
Part 4) Option c [tex]16\pi\ ft^{2}[/tex]
Part 5) Option b. [tex]12.25\pi\ m^{2}[/tex]
Step-by-step explanation:
Part 1) What is the area of a circle with a diameter of 12.6 in.?
we know that
the area of a circle is equal to
[tex]A=\pi r^{2}[/tex]
we have
[tex]r=12.6/2=6.3\ in[/tex] -----> the radius is half the diameter
substitute the values
[tex]A=(3.14)(6.3^{2})=124.63\ in^{2}[/tex]
Part 2) Which explanation can be used to derive the formula for the circumference of a circle?
First find the relationship of the circumference to its diameter by finding that the length of the diameter wraps around the length of the circumference approximately π times.
Use this relationship to write an equation showing the ratio of circumference to diameter equaling π
so
[tex]\frac{C}{D}=\pi[/tex]
Rearrange the equation to solve for the circumference
[tex]C=\pi D[/tex]
Substitute the diameter for 2 times the radius
[tex]D=2r[/tex]
[tex]C=2\pi r[/tex]
Part 3) we know that
If n increases
then
the product ns get closer to the circumference of the circle
so
the circumference of a circle is equal to [tex]C=2\pi r[/tex]
therefore
As n increases, ns get closer to [tex]2\pi r[/tex]
Part 4) What is the area of a circle whose radius is 4 ft?
we know that
the area of a circle is equal to
[tex]A=\pi r^{2}[/tex]
we have
[tex]r=4\ ft[/tex]
substitute the values
[tex]A=(\pi)(4^{2})=16\pi\ ft^{2}[/tex]
Part 5) The circumference of a circle is 7π m.
What is the area of the circle?
we know that
The circumference of a circle is equal to
[tex]C=2\pi r[/tex]
we have
[tex]C=7\pi\ m[/tex]
substitute and solve for r
[tex]7\pi=2\pi r[/tex]
[tex]r=3.5\ m[/tex]
Find the area of the circle
the area of a circle is equal to
[tex]A=\pi r^{2}[/tex]
substitute
the area of a circle is equal to
[tex]A=\pi (3.5^{2})=12.25\pi\ m^{2}[/tex]