Hans
Walser, [20260619]
Invariant
Area
Suggestion:
M. K., V.
The lens
(Fig. 1) is bounded by two parabolas whose vertices are perpendicular to each
other and are a constant distance apart.

Fig.
1: Invariant Area
The
yellow area remains invariant.
Calculation.
Affine
distortion.
Cavalieri's
Principle (Fig. 3).

Fig. 2: Cavalieri's Principle