A rainbow is a circle if viewed from the air, and it is sometimes not even that, if it is faint enough
A semicircle means a half circle.
A rainbow is a circle. What we see from almost any point on earth is a semicircle, or just a part of the rainbow. We can only see it from horizon to horizon, or just an arc of the whole rainbow. Occasionally we can see a full circle of a rainbow in the sky surrounding the sun, and sometimes multiple ones.
Semicircle is HALF of a circle!
Half of A circle
becaz the critical angle of rainbow is so large......
It is a half a circle STUPID!!!!!