Saturday, September 24, 2011

How to construct (draw) tangents to a circle through an external point - Math Open Reference

How to construct (draw) tangents to a circle through an external point - Math Open Reference

Finding the center of a circle with compass and straightedge or ruler - Math Open Reference

Finding the center of a circle with compass and straightedge or ruler - Math Open Reference

How to copy an angle with compass and straightedge or ruler - Math Open Reference

How to copy an angle with compass and straightedge or ruler - Math Open Reference

Constructing 75, 105, 120, 135, 150 degree angles and more - Math Open Reference

Constructing 75, 105, 120, 135, 150 degree angles and more - Math Open Reference

How to construct (draw) a 90 degree angle with compass and straightedge or ruler - Math Open Reference

How to construct (draw) a 90 degree angle with compass and straightedge or ruler - Math Open Reference

How to construct (draw) a 45 degree angle with compass and straightedge or ruler - Math Open Reference

How to construct (draw) a 45 degree angle with compass and straightedge or ruler - Math Open Reference

How to construct (draw) a 30 degree angle with compass and straightedge or ruler - Math Open Reference

How to construct (draw) a 30 degree angle with compass and straightedge or ruler - Math Open Reference

How to bisect an angle with compass and straightedge or ruler - Math Open Reference

How to bisect an angle with compass and straightedge or ruler - Math Open Reference

How to construct (draw) a 60 degree angle with compass and straightedge or ruler - Math Open Reference

How to construct (draw) a 60 degree angle with compass and straightedge or ruler - Math Open Reference

Friday, September 23, 2011

Pythagorean theorem


In any right triangle, the area of the square whose side is the hypotenuse (the side opposite the right angle) is equal to the sum of the areas of the squares whose sides are the two legs (the two sides that meet at a right angle).
The theorem can be written as an equation relating the lengths of the sides ab and c, often called the Pythagorean equation:[1]
a^2 + b^2 = c^2\!\,
where c represents the length of the hypotenuse, and a and b represent the lengths of the other two sides.

Other forms

As pointed out in the introduction, if c denotes the length of the hypotenuse and a and b denote the lengths of the other two sides, Pythagoras' theorem can be expressed as the Pythagorean equation:
a^2 + b^2 = c^2\,
If the length of both a and b are known, then c can be calculated as follows:
 c = \sqrt{a^2 + b^2}. \,
If the length of hypotenuse c and one leg (a or b) are known, the length of the other leg can be calculated with the following equations:
a = \sqrt{c^2 - b^2}. \,
or
b = \sqrt{c^2 - a^2}. \,
The Pythagorean equation provides a simple relation among the three sides of a right triangle so that if the lengths of any two sides are known, the length of the third side can be found. Another corollary of the theorem is that in any right triangle, the hypotenuse is greater than any one of the legs, but less than the sum of them.
A generalization of this theorem is the law of cosines, which allows the computation of the length of the third side of any triangle, given the lengths of two sides and the size of the angle between them. If the angle between the sides is a right angle, the law of cosines reduces to the Pythagorean equation.

Arabic Children's Nasheed --- Noon Noon

Friday, September 16, 2011

Top students of Grade 5 Scholarship examination

According to the results released by Department of Examinations, three students scored 195 marks and become island first in Grade Five Scholarship examination conducted in August, 2011. These students are Oshadhi RashiprabhaFonseka of Kalutara Balika Maha Vidyalaya, Nethmi Ranaweera of Miriswatta Maha Vidyalaya, Dodamgoda andNaleem Zaky Ahamed of Kekirawa Muslim Maha Vidyalaya.