5 circles.
5
It was used by the Ancient Greeks, instead of having medals, they would have the trophies in the shape of the rings in Gold, Silver, Bronze, and Iron
you use circles to make stuff round
they use protractors to measure circles
A pair of compasses are use to construct circles and arcs of circles
The question is misguided. You do not use radius only on circles!
you can use numbers by saying 5 circles than 9 squares and 7 pentagon's that will go on and on
The name for the units scientists use for circles are degrees.
There is no definitive answer on how long circles have been in use. The moon and sun are both circles and they have existed since the beginning of time.
5 circles in the oylmpic rings
To use a protractor for circles you find the middle of the circle and you then put the dot on the hole then you measure