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Wednesday, 15 September 2010

hannan learns area of a circle

'Ya Allah berikan cintaMu kepadaku, jadikanlah orang yang mencintai-Mu mencintaiku, dan jadikanlah aku mencintai segala yang membawa kepada kecintaanMu'


"Jika Anda tidak memulai hari ini dengan senyuman, belum terlambat untuk mencubanya pada hari esok."



hannan learns area of a circle









The area of a circle is the number of square units inside that circle. If each square in the circle to the left has an area of 1 cm2, you could count the total number of squares to get the area of this circle. Thus, if there were a total of 28.26 squares, the area of this circle would be 28.26 cm2 However, it is easier to use one of the following formulas:
A = Pi times r squared  or  A = Pi times r times r



http://www.mathgoodies.com/lessons/vol2/circle_area.html







A circle is a simple shape of Euclidean geometry consisting of those points in a plane which are equidistant from a given point called the centre (or center; cf. American and British English spelling differences). The common distance of the points of a circle from its centre is called its radius.

Circles are simple closed curves which divide the plane into two regions, an interior and an exterior. In everyday use, the term "circle" may be used interchangeably to refer to either the boundary of the figure (also known as the perimeter) or to the whole figure including its interior. However, in strict technical usage, "circle" refers to the perimeter while the interior of the circle is called a disk. Thecircumference of a circle is the perimeter of the circle (especially when referring to its length).

A circle is a special ellipse in which the two foci are coincident. Circles are conic sections attained when a right circular cone is intersected with a plane perpendicular to the axis of the cone.


http://en.wikipedia.org/wiki/Circle



A circle's area is found using the formula:
But where does this formula come from?
Let's find out ...


http://www.worsleyschool.net/science/files/circle/area.html

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