The image above is a pentagon.

To compute the area of a pentagon, one essential parameter is needed and this parameter is length of side (a).

The formula for calculating the area of a pentagon:

A = a^{2}√^{(5(5 + 2√5)} / _{4}

Where;

A = Area of the pentagon

a = length of side

Let’s solve an example;

Find the area of the pentagon when the length of side is 30 cm.

This implies that;

a = length of side = 30 cm

A = a^{2}√^{(5(5 + 2√5)} / _{4}

A = 30^{2}√^{(5(5 + 4.47)} / _{4}

A = 900√^{(5(9.47)} / _{4}

A = 900√^{47.36} / _{4}

A = 900√11.84

A = 900 x 3.44

A = 3096

Therefore, the **area of the pentagon** is **3096 cm ^{2}.**

**Calculating the length of side using the area of the pentagon.**

a = √(^{4A} / _{√5(5 + 2√5)})

Where;

a = length of side

A = Area of the pentagon

Let’s solve an example;

Find the length of side with an area of 150 cm^{2}.

This implies that;

A = Area of the pentagon = 150 cm^{2}

a = √(^{4A} / _{√5(5 + 2√5)})

a = √(^{4 x 150} / _{√5(5 + 1.148)})

a = √(^{600} / _{√5(6.148)})

a = √(^{600} / _{√30.74})

a = √(^{600} / _{5.54})

a = √108.30

a = 10.41

Therefore, the **length of side** is **10.41 cm.**

Nickzom Calculator – **The Calculator Encyclopedia** is capable of calculating the area of a pentagon.

To get the answer and workings of the area of a pentagon 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 **Mensuration**** **under the **Mathematics** section

Now, click on** Area of a Pentagon **under **Mensuration**

The screenshot below displays the page or activity to enter your value, to get the answer for the area of a pentagon according to the respective parameter which is the **length** **of side (a).**

Now, enter the values appropriately and accordingly for the parameter as required by the **example** above where the **length of side (a) **is **30 cm.**

Finally, **Click on Calculate**

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