x^2 + y^2 = r^2
Type your answer here. Find the radius for a circle with the equation x2 plus y2 equals 9? ..
Area of a circle equals pi (~3.14) multiplied by the radius squared. So to find the area of that circle your equation is (3.14)(3)^2 which equals approximately 27.
The inner circle is x2 + y2 = 4. The radius of the inner circle is the square root of 4, which is 2. To find the radius of the outer circle, multiply 2 times 4. The radius of the outer circle is 8. Square 8 (82 or 8 x 8) to find the number to put into the equation of the outer circle. This is 64. The equation for the outer circle is x2 + y2 = 64.
x2 +y2 = R2 =16 = radius 2 R = 4
The circumference of a circle equals 2 times pi times the radius, in this case, about 31.42 inches.
The centre is (3,-1) and the radius is sqrt(10).
Area of a circle equals pi r2 Therefore the radius of a circle equals the square root of (area divided by pi).
Equation for the area circle = pi x radius squared If the area is 144pi, then you need to find the square root of 144, which is 12. Therefore, radius = 12
OK, SO to find the area of a circle, you find the radius (half of the diameter), and fit it into the equation πr2=A where r equals radius and A = area. The perimeter of a circle is π multiplied by the diameter. π is ≈ 3.1415296.
Half the square root of the square radius equals the circle radius.
x2+y2+4x+2y+3=0(x+2)2 + (Y+2.5)2 = 3This is the equation of circle with center at (-2,-2.5) with radius 3.5
you cant: pi is the same for any circle - 3.1415... the diamter or the radius has to be given diameter divided by two equals the radius the radius times two equals the diameter