Question

why is the length of the day and night equal on 21 march​

Answer 1

Days and nights are equal at all places on earth on March 21 because on this day sun rays will fall in the vertical direction towards the equator or at the center position of the earth. This supplies the equal light distribution from pole to pole which makes the day and night duration.

Answer 2

Answer:

Because to supply the equal light distribution from Pole to Pole on this day which makes the equal day and night.

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