The image above represents friction angle.

To compute for friction angle, two essential parameters are needed and these parameters are **Uniaxial Compressive Strength (σ _{c})** and

**cohesion (c).**

The formula for calculating the friction angle:

φ = 2tan^{-1}(^{σc – 2c} / _{σc + 2c})

Where;

φ = Friction Angle

σ_{c} = Uniaxial Compressive Strength

c = Cohesion

Let’s solve an example;

Find the friction angle when the uniaxial compressive strength is 11 and the cohesion is 22.

This implies that;

σ_{c} = Uniaxial Compressive Strength = 11

c = Cohesion = 22

φ = 2tan^{-1}(^{σc – 2c} / _{σc + 2c})

φ = 2tan^{-1}(^{11 – 2(22)} / _{11 + 2(22)})

φ = 2tan^{-1}(^{11 – 44} / _{11 + 44})

φ = 2tan^{-1}(^{-33} / _{55})

φ = 2tan^{-1}(-0.6)

φ = 2(-30.96°)

φ = -61.927

Therefore, the **friction angle **is **-61.927.**

Nickzom Calculator – **The Calculator Encyclopedia** is capable of calculating the friction angle.

To get the answer and workings of the friction angle using the **Nickzom Calculator – The Calculator Encyclopedia. **First, you need to obtain the app.

You can get this app via any of these means:

**Web** – https://www.nickzom.org/calculator-plus

To get access to the **professional **version via web, you need to **register** and **subscribe **for** NGN 1,500 **per** annum** to have utter access to all functionalities.

You can also try the **demo **version via https://www.nickzom.org/calculator

**Android (Paid)** – https://play.google.com/store/apps/details?id=org.nickzom.nickzomcalculator

**Android (Free)** – https://play.google.com/store/apps/details?id=com.nickzom.nickzomcalculator

**Apple (Paid)** – https://itunes.apple.com/us/app/nickzom-calculator/id1331162702?mt=8

Once, you have obtained the calculator encyclopedia app, proceed to the **Calculator Map, **then click on **Geology**** **under **Add-on.**

Now, Click on **Rock Mechanics**** **under **Geology**

Now, Click on **Friction Angle** under **Rock Mechanics**

The screenshot below displays the page or activity to enter your values, to get the answer for the friction angle according to the respective parameters which are the **Uniaxial Compressive Strength (σ _{c})** and

**cohesion (c).**

Now, enter the values appropriately and accordingly for the parameters as required by the **Uniaxial Compressive Strength (σ _{c})** is

**11**and

**cohesion (c)**is

**22**

**.**

Finally, Click on Calculate

As you can see from the screenshot above, **Nickzom Calculator**– The Calculator Encyclopedia solves for the friction angle and presents the formula, workings and steps too.