Question

why rainbow always appear semicircle in shape

Answer 1

Actually rainbow is always in a circular shape but the earth comes in contact with it in path so it seems like semicircular and sometimes it is also a case when there is no dispersion of light.Hope this helped.

Answer 2

rainbow always appear in semi circle shape because our earth is in round shape and in such a manner that v can only see semi circular shaped rainbow.also our eye can see 40°-44°.and also rainbow is actually in a whole circular shape