# Culture, General Things, Mathematics, Geometry

Geometry is in Mathematics.

Culture, General Things, Mathematics, Geometry, Circle

Circle. A circle is an ellipse with equal width and height; a = b.

The ellipse equation when a = b: x2/a2 + y2/a2 = 1 or simplified ( x2 + y2 ) / a2 = 1 or y = ( a2 - x2 )1/2.

A circle has an eccentricity of 0.

PI is the ratio of diameter and circumference of a circle. It is a Transcendental Number.

Plane Curve. A Plane Curve is defined by its eccentricity:

= 0 = Circle

> 0 and < 1 = Ellipse

= 1 = Parabola

> 1 = Hyperbola

Eccentricity is the relationship between the height and width of an ellipse ie if a is the width, and b is the height the eccentricity = ( 1 - a2 / b2 )½

If a = b, which is the case for a Circle, the eccentricity is 0.

If a / b, or b / a is less than 1 then it is an Ellipse.

Culture, General Things, Mathematics, Geometry, Eccentricity

Eccentricity is the relationship between the height and width of an ellipse ie if a is the width, and b is the height the eccentricity = ( 1 - a2 / b2 )½

If a = b, which is the case for a Circle, the eccentricity is 0.

If a / b, or b / a is less than 1 then it is an Ellipse.

Ellipse. 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.

The equation for a standard ellipse with width 2a and height 2b is ( x2 / a2 ) + ( y2 / b2 ) = 1.

An ellipse has an eccentricity of > 0 and < 1.

Circle. A circle is an ellipse with equal width and height; a = b.

The ellipse equation when a = b: x2/a2 + y2/a2 = 1 or simplified ( x2 + y2 ) / a2 = 1 or y = ( a2 - x2 )1/2.

A circle has an eccentricity of 0.

Culture, General Things, Mathematics, Geometry, Ellipse

Ellipse. 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.

The equation for a standard ellipse with width 2a and height 2b is ( x2 / a2 ) + ( y2 / b2 ) = 1.

An ellipse has an eccentricity of > 0 and < 1.

Plane Curve. A Plane Curve is defined by its eccentricity:

= 0 = Circle

> 0 and < 1 = Ellipse

= 1 = Parabola

> 1 = Hyperbola

Eccentricity is the relationship between the height and width of an ellipse ie if a is the width, and b is the height the eccentricity = ( 1 - a2 / b2 )½

If a = b, which is the case for a Circle, the eccentricity is 0.

If a / b, or b / a is less than 1 then it is an Ellipse.

Culture, General Things, Mathematics, Geometry, Plane Curve

Plane Curve. A Plane Curve is defined by its eccentricity:

= 0 = Circle

> 0 and < 1 = Ellipse

= 1 = Parabola

> 1 = Hyperbola