sirkel.. sirkel.. sirkel..

Sebelum nulis artikel tentang lingkaran ini, izinkanlah saya untuk sumbang suara saya yang nggak sumbang ini (nah lho, bingung nggak ama kata" gua ) Hahay  :p
Mari nyanyi : "Lingkaran kecil.. lingkaran kecil.. lingkaran besar.. Diberi pisang.. diberi pisang.. nggak mau makan.. Enam.. enam.. 36. Enam.. enam.. diberi sudut"
Gila gokil banget kan lagunya
Masa habis ngomongin lingkaran, nyambung ke pisang, nyambung ke angka 6 sama 36, trus sudut. Imajinatif banget ya tu manusia yang nyiptain lagu

Imut kan? Imut kan? *Cuih

Yasudah, daripada diterusin ocehan saya yang gaje ini.. Langsung aja ngebahas materi. Yuk mariii..

A circle is a simple shape consisting of points in a plane which are equidistant from given point called centre. It’s a simple closed curve which divide the plane into two regions, interior and exterior.

Below are some definition which related to a circle:

Arc                             : A curved line that is part of the circumference of a circle.

Chord                         : A line segment within a circle that touches 2 points on the circle.

Circumference         : The distance around the circle.

Diameter                   : The longest distance from one end of a circle to the other.

Phi (µ)                         : A number, 3.141592..., equal to the circumference / the diameter of any circle.

Radius                         : The distance from center of circle to any point on it.

Sector                         : A circle wedge.

Tangent of circle     : A line which perpendicular to the radius that touches only one point on the circle.

 

Formulae

Circumference   = 2µr

Because 2r             = d, so Circumference = µd

 Area    = µr²

*µ         =  22/7 or 3.14

  r         = radius

 d         = diameter 

 

Tangent line

• The line drawn perpendicular to a radius through the end point of the radius is a tangent to the circle.

• A line drawn perpendicular to a tangent through the point of contact with a circle passes through the centre of the circle. 

• Two tangents can always be drawn to a circle from any point outside the circle, and these tangents are equal in length.

I²          = d² – (R-r)²

O²           = d² + (R-r)²

* I        = Inner tangent line

  O       = Outer tangent line

  d        = Diameter between two center points

  R        = First radius,   r   = Second radius