Orbits sould be circular because the centripetal force that keeps objects in circular motion is constant (it is gravity!)
the gravity of the sun pulls them in a circular motion.
stone
Dome
A dome
they built keeps so that they could see there enemies and attack them
A body moving in a circular path has no fixed direction. Its direction keeps on changing with every step of its motion.
co circular activities should made compulsory because they keeps your mind fresh and healthy
Stone keeps are built on top of a hill to get the vantage point.
Well, the buildings are against the wall , which makes it a shell keep however it is not circular , most common shell keeps are circular
No, centrifugal force is fictitious force, peculiar to circular motion, that is equal but opposite to the centripetal force that keeps a particle on a circular path.
It's called a kiva.