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A = pi r^2
Commit this to memory; it is very elementary maths.
Where
'A' is the Area and 'r' is the radius.
In words 'Area ( of a circle) is equal to 'pi' multiplied to the radius squared'.
Similarly for the circumference of a circle.
C = 2pir or C = pi*d
Where 'C' is the circumference of the circle, 'r' is the radius or 'd' is the diameter.
NNB 'pi' ~ 3.14 for elementary school purposes. This is only an approximation for 'pi' as it is an irrational number ; the decimals are in no particular order and go to infinity. Closer approximations are 3.1416 , or 3.141592654....
lenpollock
Wiki User
∙ 2012-05-15 23:39:14Find the circumference of a circle with radius 5 ft.
Area of a circle. The area of a circle of radius r is given by the polynomial πr2. Use 3.14 as an approximation for π.
Anonymous
28 in long need to know how big to make a circle
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How do you find the area of a circle when the radius is unknown?
By using the other information supplied about the circle to calculate either its radius (from which its area can be calculated) or its area (if the circle is similar to another with a given area and some ratio between the two circle is given):If the diameter is given: radius = diameter ÷ 2If the circumference is given: radius = circumference ÷ 2πIf the circle is similar to another circle which has a given area, and the length ratio is given; square the length ratio to get the area ratio and apply to the given area.
What is the formula to find the area of a circle with the radius given?
A = pi x radius squared where pi = 3.14
How do you find the area of a cirlcle?
The area of a circle is given by the formula A=pi x r2 Where A is the area of the circle, pi is a constant approximately equal to 3.1415, and r is the radius of the circle. So, to find the area of a circle with a radius of 5cm you would first square the radius -- 25 cm2. Then times by pi. So the answer would be 25pi cm2.
What is the radius of a circle if the area is 153.86cm2?
The area of a circle is 153.86cm².find the radius of the circle
How do you find the radius of a circle if you only know the area?
Radius = +sqrt(Area/pi)
How do you find the radius of an inscribed circle of a square given the area of the circle?
If yo have the area of the circle, the square is irrelevant. Radius = sqrt(Area/pi)
How do you find a area a circle?
The answer depends on what information you are given.
How do you find radius when area is given?
Divide the area by pi and then square root it this will give the radius of the circle.
How do you find the area of a circle when the radius is unknown?
By using the other information supplied about the circle to calculate either its radius (from which its area can be calculated) or its area (if the circle is similar to another with a given area and some ratio between the two circle is given):If the diameter is given: radius = diameter ÷ 2If the circumference is given: radius = circumference ÷ 2πIf the circle is similar to another circle which has a given area, and the length ratio is given; square the length ratio to get the area ratio and apply to the given area.
How do you find the radius of a circle when given only the area?
Area = pi*radius2 So, radius = sqrt(area/pi)
How do you find the radius of a circle when your given the area?
a=area p=pi r=radius sqr(a/p)=r
How do you find the radius of an inscribed circle of a square given the area of the square?
Half the square root of the square radius equals the circle radius.
How do you find the area of a circle without knowing the radius?
If the circumference or diameter is given then you can find the radius or simply measure the distance from the centre of the circle to the circumference.
What is the formula to find a area of a circle when given radius?
A = pi x radius2
What is the formula to find the area of a circle with the radius given?
A = pi x radius squared where pi = 3.14
Find the area and perimeter of a given circle?
If 'R' is the radius of the circle, then-- area of the circle is [ pi R2]-- perimeter of the circle is [ 2 pi R ]
How can you calculate the radius with the area given to you?
Area of a circle = pi x radius squared, so to get the radius, divide the Area by pi (3.14159), and then find the square root of that
