Math Story : Introduction To Perimeter

The Electric Fence

“We will steal more animals from the sanctuary and sell them at a higher price. We will get rich and richer. Haha!” says Asquarho boss and Acirho boss.

Soon the news of attack on the sanctuary is detected by Mr Messenger. He immediately informs the kids. “Save the animals. Acirho Boss and Asquarho Boss are planning to steal them”, he says and leaves.

“What! This is so cruel. We cannot let them harm our animals. We should save them”, says Cirha. Her love for animals and plants is immeasurable. Triho agrees with her. They decide to make a plan to save the animals.

“How about we shift the animals?” suggests Cirha. “Brilliant! Yes, let us shift the animals to another place. Later add strong electric fencing for protection. When touched, this fence will give shocks to the intruder. This way, the villains will not be able to touch the animals”, says Triho. They are ready with their plan.

It is time for execution. Triho and Cirha first decide on a place to shift the animals. “Yes, this rectangular ground looks perfect. The
animals will also have ample space to roam around”, says Cirha. It is time to add the fencing. “But how much wire do we need?” thinks Triho.

After thinking hard, Cirha has found a solution may be. “Because we need to add the fence around this rectangular ground, we can just measure the border length right?” she says. “Exactly!” says a male voice. They turn around to find Uncle Math standing behind. “We are glad that you are here”, says Triho.

“To find the length of the wire needed for fencing, we need to find the perimeter. The distance around a shape gives us its
perimeter. As Cirha said, to find the perimeter, we have to measure the border of the rectangular ground”, explains Uncle
Math.

“Yay! I was right. Let us measure the border length using handspans or foot spans”, suggests Cirha. “No, that would take a lot of time, and we might get confused too”, says Triho.

Uncle Math draw a rectagular shape ground on board and said “We just count the square used in the border? One square is equals to 10 handspans, that would be quick and easy. Now tell me total numbers of the squares”.

Immediately Triho and Cirha start counting the squares. Triho counts the two opposite longer sides, and Cirha counts the two
opposite shorter sides.

“Alright! So how much is the perimeter?” asks Uncle Math. “My two sides are 10 squares long”, says Triho. “My two sides are 6
squares long”, says Cirha. “But how much in total?” asks Uncle Math. Triho quickly starts adding 10 + 10 + 6 + 6. Can you tell how
much is the perimeter?

“32”, says Triho. “Correct. Because we used the squares of dimensions one unit each, we say the perimeter of this rectangle is 36 square units”, says Uncle Math. “But counting these squares every time is a tedious task. Do we have a shortcut?” asks Cirha.

“Yes, there is one. All you did was add the lengths twice and breadths twice right? So the formula to find the perimeter of the rectangle is 2 times the sum of its length and breadth”, says Uncle Math. “Oh this is so simple now”, says Cirha.

Having calculated the perimeter, the kids now quickly get the wires for fencing. “Phew! We are done! The fence looks great. Let us shift the animals now and later switch on the power button”, says Triho.

“Perfect!” says Uncle Math. All three of them wait for the boss villains to arrive.

Meanwhile, the villain’s spacecraft is not working. “We can fix this later, first let us search the animals”, says Acirho Boss. They decide to walk around the sanctuary to find the animals.

Having no trace of the animals, they are confused. “Are the animals hidden somewhere?” says Asquarho Boss. They continue their search.

“Hey, look there”, says Acirho Boss excitedly. Suddenly, their eyes light up seeing the animals. “Hurrah! Let us quickly go and steal them”, says Asquarho Boss. They rush near the rectangular ground.

As they step inside to enter the ground, the electric fencing gives them a powerful shock. “Ahhhhh!” they scream out of pain.

They try to enter from the other side. But the same thing happens. Triho, Cirha and Uncle Math secretly laugh from a corner seeing them struggle.

“They have secured the ground using electric fencing! We won’t be able to succeed today. Let us leave now”, says Acirho boss. “Argghhh! I am sure Triho must have done this. I will teach him a lesson”, says Asqurho boss, and they leave in frustration.

“Hurrah! We did it”, say the kids. They are delighted to see the animals safe and alive. Uncle Math is proud of them. “However difficult the task is, if there is a will to do it, we find a way to do it. You guys are a perfect example of this”, says Uncle Math. A challenge, a good intention and a brilliant idea, it was an action-filled day indeed.

We Learnt That…

• Perimeter is the distance around a shape.
• To find the perimeter, we add the length of all the sides.
• Perimeter of rectangle = 2 (length + breadth)
• Animals also deserve to stay safe and healthy.

Let’s Discuss

• What were Asquarho Boss and Acirho Boss planning?
• What was our plan to save the animals?
• How did we find the total length of the wire needed for fencing?
• What is the perimeter? How do we find it?
• We tried our best to save the animals. Would you do the same?