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Circle

★★☆☆☆Middle School

📖Definition

The set of all points in a plane that are at a fixed distance from a center point.

C = 2π r = π d

Circumference

A = π r²

Area of circle

(x-a)² + (y-b)² = r²

Circle equation with center (a, b), radius r

예제 1★☆☆☆☆

Find the circumference and area of a circle with radius 7cm. (π ≈ 3.14)

예제 2★★☆☆☆

Find the radius of a circle with area 100π cm².

Wheel, gear design

Domes, circular structures

#geometry#circle#fundamental