Ellipsov is called a geometrical figure on the plane which is set formuloykh²/a² + by y²/b² = 1dlya creation of an ellipse by means of compasses and a ruler, it is necessary to construct points to it belonging.

## Instruction

1. Let's enter the definitions connected with a concept of an ellipse. Two points of F1 and F2 are called ellipse focuses if for any point of the M F2M taken on an ellipse, the sum of distances of F1M + is a constant. AB piece passing through focuses which ends lie on an ellipse is called a big half shaft. CD piece perpendicular to a piece of AB and passing through its middle is called a small half shaft.

2. Let lengths of axes of an ellipse of AB and CD be given. For construction an ellipse it is possible to use the following algorithm. Let's draw two perpendicular lines and from a point of intersection we will postpone pieces equal AB/2 and down equal to CD/2 across

3. Let's draw two circles radiuses of AB/2 and CD/2. From the center of a circle we will carry out several beams.

4. Through points of intersection of the constructed beams with circles we will carry out the pieces parallel to ellipse axes.

5. Let's allocate points of intersection of the constructed pieces, it will be the points belonging to an ellipse.

6. Having connected the received points, we will receive an ellipse.