What does a RADIAN have to do with a RADIUS?

Question

I thought radian was measure of an angle!!!

Answer 1

radian is a  measurement of arc length and you need a radius to draw that arc.  it has to do with polar coordinate system.  if you were to look down on top of a globe you would see the longitudinal lines forming a x... pick one to be x the other at 90 degrees to be y.  the the latitudinal lines form a circle.  This is a what a polar coordinate system looks like.

Answer 2

A radian is an angle measure.  Radius is the distance from the center point of a circle to the edge of the circle.

Answer 3

Everything!

Draw a circle and mark off along the circumference the length of one radius. Mark off another radius length from the first one and keep doing that until you have completed the circle.

I don't have to tell you that you will have marked off 2pi radii (circumference = pi D). The angle subtended at the center of the circle between any two adjacent radius length marks is one radian. Hence the name.  

Answer 4

A radian is basically measuring angles with the length of the radius.  Basically, you take the length of the radius, and wrap it around the circumference, to get an arc with an angle of 1 radian, since you used one radius.  The ratio, naturally, is r/2r(pi) = 1/2pi.  Therefore, you need 2pi radians to complete the length of the circle.

Answer 5

radian = arc length / radius