# What is One radian ? Relationship Between Degree and Radian Geometrically Proof

If we are going to learn about angles then we must know about the unit of measuring angles.There are many units to measure angles like degree, grade, radian etc. Radian is Standard Unit (SI unit) of measuring plane angle.  So it is very necessary to know the definition of one radian, how we have definite the unit of angle. The unit of angle – one radian is define as

The  angle formed at center of the circle by an  arc equal to its radius.

In the following  video, addition to definition of one radian we derive the relationship between the two units of angles degree and radian.We get the relation as

With the help of this relation between degree and radian we can easily convert the angle value given in radian into degree as well as angle value given in degree into radian. There is a small example too given in this video. I hope you will learn something from this video. Please dont forget to put your comment below.

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