Introduction of Drawing Circles:

Circle can be made by drawing an arc with center point to make one complete revolution. The circle can be represented as the symbol `@` . The distance from the center point of the circle and the end of the arc on the circle is always equal to any point on the arc. Simply says, the circle is the closed loop of the line. Let us see how to draw circle with a compass.

Drawing Circles with a Compass:

Procedure for drawing circles with compass:

 Measure x unit by compass and to draw circle

  circle to draw by compass as the radius of x unit


Step 1: Draw a reference line and mark one point as center.

Step 2: Take the compass and measure x length by using ruler.

Step 3: Place the tip of the compass on the center point and make the circle.

Step 4: Thus the taken length in the ruler by using compass is called the radius of the circle.

Thus by following the above procedure we can drawing circles can draw with a compass.

Formula: Area of the circle = πr2

Perimeter of the circle = 2πr

Properties of Circles:

 Properties of circle

Diameter: The line segment that passed through the center of the circles, where the both end point of the line segment is on the circle.

Radius: Half of the diameter of the circles is called radius of the circles.

Chord: The line segment that does not pass through the center of the circles, where the both end point of the line segment is on the circles.


 Sector of the circle

A circle cut by the two radius of the same circle. The angle at the center of the circle is measured as theta (in radians) and alpha in degrees. The area cut by two radius of the circle is represented as K and arc length is represented as s.

Formula: K = `(r^2 theta)/(2)` 

K = ( r2 alpha ) * `(pi)/(360^0)`


 Theta θ = `(s)/(r)`

K = `(sr)/(2)`

Tangent: At a single point, the line touches the circle.

Secant: It is nothing but the extension of the chord.