Adjective:

আফ্রিকার নিগ্রোসংক্রান্ত,

nephroid's Usage Examples:

In geometry, a nephroid (from the Greek ὁ νεφρός ho nephros) is a specific plane curve whose name means 'kidney-shaped' (compare nephrology).

parabola, ellipse, nephroid).

circle Epicycloid examples k = 1          a cardioid k = 2          a nephroid k = 3 - resembles a trefoil k = 4 - resembles a quatrefoil k = 2.

(including perfectly parallel rays, as if from a point source at infinity), a nephroid-shaped patch of light can be produced.

at the bottom of a cylindrical cup is half of a nephroid, which looks quite similar.