Circle Solving Equations ( For Visual Basic)

If the radius is known:

    Diameter D = 2*R

    Circumference C =Pi*D or C = 2*Pi*R

    Area A = Pi*R*R

If the diameter is known:

    Radius R = D/2

    Circumference C =Pi*D or C = 2*Pi*R

    Area A = Pi*R*R

If the Circumference is known:

    Radius R = C/(2*Pi)

    Diameter D = 2*R or D = C/Pi

    Area A = Pi*R*R or A = (C*C)/(4*Pi)

If the Area is known:

    Radius R = Sqr(A/Pi)

    Diameter = 2*Pi or D = 2*Sqr(A/Pi)

    Circumference C = 2*Pi*R or C = Pi*D or C= 2*Pi*Sqr(A/Pi)

Remember that Pi is about 3.14159 but can be calculated by:

    Pi = 4*ATN(1) (Click here to understand why this works)