Law of Cosine States the relation between the Sides and Angle of triangle. It states that, if the length of two sides and the angle between them is known for a triangle, then we can determine the length of the third side.

Select Which value you are providing ((Side(a) , Side(b) , Side(c)) and (Side(b) , Angle(A), Side(c)) and (Side(a) , Angle(B) , Side(c)) and (Side(a) , Angle(C) , Side(b)) input value and click on Calculate.

##### Law of Cosine

A=Angle A

a=Side a

B=Angle B

b=Side b

C=Angle C

c=Side c

K=Area

s=SemiPerimeter

P=Perimeter

r=Radius of inscribed circle

R=Radius of circumscribed circle

Calculation Options

Inscribed Circle Radius

r =

Circumscribed Circle Radius

R =

### How to use Law Of Cosine Calculator?

Step by step procedure for Law Of Cosine Calculator is as follows.

**Step 1: **Select which value you will be providing? Dropdown list has Side (a) , Side (b) , Side (c) and Side (b) , Angle (A) , Side (c) and Side (a) , Angle (B), Side (c) and Side (a) , Angle (C), Side (b) options.

**Step 2: **Input appropriate value as per selected type in Step 1.

**Step 3: **Now click on "Calculate" button to get result.

You will get Angle (A) , Angle (B) , Angle (C) , Side (a) , Side (b) , Side (c), Area (K) , Perimeter (P) , SemiPerimeter (s) , Altitude of Side Length (ha) , Altitude of Base (hb) , Altitude of Hypotenuse (hc) , Inscribed Circle Radius (r) , Circumscribed Circle Radius (R) as per your value input.