Area of circle is pi x radius squared
Circumference is p x diameter
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Rem4 x 3.14 ember the Circle Equations C = 2 pi r A = pi r^(2) If 'r' (radius) = 2 units then C = 2 pi x 2 = 4 x pi = 4 x 3.14 = 12.56 units. A = pi 2^(2) = 3.14 x 4 = 12.56 units^(2) NB pi = 3.141592.... It is an irrational constant. However, when learning circle equations you are usually given pi = 3.14 , or 3.1416 or 22/7, These are only approximations given for ease of learning.
NO!!!! C = 2 pi r C = pi d In words ; Circumference equals two times 'pi' times radius or , circumference equals 'pi' times diameter. NB The diameter is twice the radius. Also A = pi r^(2) In words, Area equals 'pi' times the radius squared. Read learn and comit to memory these two circle equations.
Area = pi R2Circumference = 2 pi RArea/Circumference = pi R2/2pi R = 1/2 R
Trigonometric equations often have infinitely many solutions, due to the periodicity of the functions. Take a simple example, sin x = 0. This equation is satisfied by an angle of zero, but also by an angle of pi, 2 x pi, 3 x pi, etc. (this is in radians; the equivalent in degrees would be 0°, 180°, 360°, etc.). Once you find two base solutions (in this case 0 and pi), repeatedly adding the length of the period (in this case, 2 pi, equivalent to 360°) will give you additional solutions.
a=pi r²a=pi (d/2)²