For the angle α, the sine function gives the ratio of the length of the opposite side to the length of the hypotenuse.. To define the sine and cosine of an acute angle , start with a right triangle that contains an angle of measure ; in the accompanying figure, angle in a right triangle is the angle of interest. The three sides of the triangle are named as follows: [1]

An ellipse (red) obtained as the intersection of a cone with an inclined plane. Ellipse: notations Ellipses: examples with increasing eccentricity. In mathematics, an ellipse is a plane curve surrounding two focal points, such that for all points on the curve, the sum of the two distances to the focal points is a constant.It generalizes a circle, which is the special type of ellipse in which ...

In geometry, a square is a regular quadrilateral, which means that it has four straight sides of equal length and four equal angles.Squares are special cases of rectangles, which have four equal angles, and of rhombuses, which have four equal sides.As with all rectangles, a square's angles are right angles (90 degrees, or π /2 radians), making adjacent sides perpendicular.

Nuclear fusion is a reaction in which two or more atomic nuclei (for example, nuclei of hydrogen isotopes deuterium and tritium), combine to form one or more atomic nuclei and neutrons.The difference in mass between the reactants and products is manifested as either the release or absorption of energy.This difference in mass arises as a result of the difference in nuclear binding energy ...