# Hollow Ellipse

on . Posted in Plane Geometry

• Hollow ellipse (a two-dimensional figure) has two ellipses with a conic section or a stretched circle.
• The major axis is always the longest axis in an ellipse.
• The minor axis is always the shortest axis in an ellipse.

## Area of a Hollow ellipse formula

$$\large{ A_{area} = \pi \; \left( a \; b - e \; f \right) }$$
Symbol English Metric
$$\large{ A }$$ = area $$\large{ in^2 }$$  $$\large{ mm^2 }$$
$$\large{ a }$$ = length semi-major axis $$\large{ in }$$ $$\large{ mm }$$
$$\large{ b }$$ = length semi-minor axis $$\large{ in }$$ $$\large{ mm }$$
$$\large{ e }$$ = length inner semi-major axis $$\large{ in }$$ $$\large{ mm }$$
$$\large{ f }$$ = length inner semi-minor axis $$\large{ in }$$ $$\large{ mm }$$
$$\large{ \pi }$$ = Pi $$\large{3.141 592 653 ...}$$

## Inner Semi-major Axis Length of a Hollow ellipse formula

$$\large{ e = a-g }$$
Symbol English Metric
$$\large{ a }$$ = length semi-major axis $$\large{ in }$$   $$\large{ mm }$$
$$\large{ b }$$ = length semi-minor axis $$\large{ in }$$ $$\large{ mm }$$
$$\large{ g }$$ = ring width $$\large{ in }$$ $$\large{ mm }$$

## Inner Semi-minor Axis Length of a Hollow ellipse formula

$$\large{ f = b-g }$$
Symbol English Metric
$$\large{ a }$$ = length semi-major axis $$\large{ in }$$  $$\large{ mm }$$
$$\large{ b }$$ = length semi-minor axis $$\large{ in }$$ $$\large{ mm }$$
$$\large{ g }$$ = ring width $$\large{ in }$$ $$\large{ mm }$$