Assertion: ellipse's area | /r/CapableOf | give following formula
Facets:
value: for the area of an ellipse
type: OTHER
Source sentences:
text: If ‘a’ stands for OA and ‘b’ stands for OB, it can be proved that the area of the ellipse can be found by substituting ‘ab’ for ‘r r’ in the formula for the area of the circle, which then gives the following formula for the area of an ellipse: