Area List

The radius of a circle I is one half the radius of circle ll. What is the ratio of the area of circle l to the area of circle ll?

Let’s say circle I has radius of 1 and circle II has a radius of 2. Find the areas:
circle I = π * 1² = π * 1 = π
circle II = π * 2² = π * 4 = 4π

find the ratio between the areas
π / 4π

1/4 or 1:4

The area of the square is 196cm squared. The area of the circle is 153.94cm squared. I need to know how to calculate what fraction the area of the circle is of the area of the square.

Help ?

Calculate the square root of the area of the square.

square root of 196 = 14.

divide that by two to get the radius of the circle
14/2 = 7

use pi*r^2 to get the area of the circle.
pi=3.14
r = 7, r squared = 49

49*3.14 = 153.86. The reason this isn’t 153.94 is because pi isn’t exactly 3.14 if you use pi to a few more digits then you’ll get 153.94. i.e. 49*3.1415926 = 153.94 approximately.

How do you figure out the area of a circle?
If the radius is 7cm then obviously the diameter is 14cm. But I can’t remember to figure out the area of a circle. is it 7*14=98 ?

Area = πr^2
Area = 3.1416(7)^2
Area = 3.1416(49)
Area = 153.93804 sqcm

How fast is the area of a circle increasing when the circumference equals 8 feet and the circumference is increasing at a rate of 7 feet per minute? The area is increasing at ? square feet per minute.

Thanks in advance for the help!

C = 2pi*r

A = pi*(C / 2pi)^2
A = C^2 / 4pi
dA / dt = (1 / 4pi) *2C * dC / dt
dA / dt = (1 / 4pi) *2(8) * (7)
dA / dt = 112 / (4pi)
dA / dt = 28 / pi

What is the diameter of a circle with an area of 81p in2?

4.5 inches

9 inches

18 inches

40.5 inches

By 81 p in2, I assume you mean 81*pi in^2

A = pi * r^2
81*pi in^2 = pi r^2
81 in^2 = r^2
Take the square root of both sides to get
9 in = r

Since the diameter is double the radius,
d = 2*9in
d = 18 in

I hope this helps!

The radius of 32mm and asks for area, and unsure with a circle, thanks!

A = r^2 * pi

32^2 * pi = approx 3217 mm^2

The only thing you know is the length of a side is 14 cm. PLEASE HELP!

also, could you find the area of the part not included in the circle?

Draw the radius of the circle from the bottom middle of the triangle to the circle’s center. Then draw a line from the circle’s center to the left vertex of the triangle. As you can clearly see, you now have a 30-60-90 triangle with one leg equal to 7 cm.

From the 30-60-90 ratio that s√3:s:2s

s√3=7

s=7√3/(3)=radius

Area of circle=pi*r^2

Area=pi*49*3/9=49pi/3

k, i have to find the circumference, diameter and radius for a quarter circle with an area of 19.93. im sorry, i usually figure these out myself, but im so stuck on this one:( any help would be appreciated. thnx<3

A=pi r^2, so knowing that you can figure out what the radius is by reworking the equation to get r by itself. once you get that, just plug and chug the numbers to get the radius. knowing that you can figure out the other things easily.

it is not the mange, we bath him by weekly, hes well groomed, but he acts like that area hurts, he bites at the area.

You did not say what color your Doberman is.

If it is a Fawn or a Blue, then it could be suffering from color dilution alopecia.
If its a Black or a red it can be suffering from follicular dysplasia.
———
Blue and fawn Dobermans often suffer from a condition called Color Dilution Alopecia (CDA). CDA is a form of follicular dysplasia (FD). Reds and blacks can suffer from FD. The symptoms of CDA include bilateral balding, which commonly begins on the flanks or along the topline and spreads down the back.
Severe cases may begin as puppies, although the vast majority of puppy problems turn out to be simple "puppy staph." In a typical case of CDA, the coat may not begin to thin until the dog is between one and three years of age. In severe (and rare) cases, all the blue (or fawn) hairs can fall out. Most often, dogs with CDA end up with very thin coats along their back and flanks, but do not go completely bald. The dogs remain healthy and happy, despite a thin coat.

You need to take this dog to a vet, do a skin scraping, test his thyroid and get him checked out in general.

I’m really stuck on my maths homework I need to find some ways to finding the area of a circle. Can somebody please help me!?

The area of a circle is pi*r^2, read as: pi-r-squared. Another way, is if you know the radius and circumference, the area of a circle is also equal to circumference times the radius, divided by 2, or A = (C*r)/2.

Finally, if you put a circle inside of a square with a length equal to the radius of the circle, the the area of the circle will always equal be .79 x A of square.