Circle: Area and Perimeter

Area and Sector





Parts of A Circle

Rendered by

Area of A Circle


Rendered by

\(A = \pi\times r^2\)

\(\pi = \dfrac{22}{7} = 3.14\)

Rendered by

\(A =\dfrac{1}{4} \pi\times d^2\)

\(\pi = \dfrac{22}{7} = 3.14\)

Area of A Sector


Rendered by

\(\text{Area of sector} = \dfrac{1}{2}\times r^2 \times \theta\)

\(\theta\) in radian


\(\text{Area of sector} = \dfrac{\theta}{360^\circ}\times \pi\times r^2\)

\(\theta\) in degree

Circumference of A Circle


Rendered by


\(\text{circumference of circle} = 2\times \pi\times r\)

\(\pi = \frac{22}{7} = 3.14\)

\(r = \text{radius}\)

Rendered by


\(\text{circumference of circle} =\pi\times d\)

\(d = \text{diameter}\)

Arc Length


Rendered by


\(\text{If θ is measured in degrees then:}\)

\(\text{Arc length} = \frac{\theta}{360^\circ} \times \text{circumference of circle} \)

\(\text{Arc length} = \frac{\theta}{360^\circ} \times 2\times \pi \times r \)


\(\text{If θ is measured in radians then:}\)

\(\text{Arc length} = \theta \times r\)


\(1 \pi \text { radians} = 180^\circ\)

\(1 \text{ radians ≈  57.3°}\)



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Kembali ke Circle: Area and Perimeter