**Circular radius of length theta:**

Where r is the radius of the circle l, is the length of the arc and theta mathematical denoted by θ is the circular measure of the central angle.

**By definition of radian:**

An angle of **1 radian** extend an arc AB on the circle of length **= 1.r**

An angle **1/2 radian extend an arc AB** on the circle of length **= 1/2.r**

An angle of **2 radians extend an arc AB** on the circle of length**= 2.r**

Therefore,

An angle of ** θ radian extend an arc AB** on the circle of length** = θ. r**

implies that means (⇒)

** ⇒ l = θ.r**

Therefore, **The Formula of theta in radian.**

**θ= l / r **

**Definition of radian and unit radian:**

Radian is the measure of the angle expanded at the center of the **circle by an arc** (mean curve), whose length is equal to the radius of the circle.

**UNIT RADIAN:**

Consider a **circle of radius r,** make an** angle ∠ AOB** at the center of the circle whose **rays cut off** an

arc **⌢ AB**

on the circle whose** length is equal to the radius.**

Thus

**m ∠ AOB= 1 radian**

### Like this:

Like Loading...

*Related*