O que é Perímetro?

🎯 What Will We Learn Today?

If you walked all the way around a shape, how far would you go? That's the perimeter! Today we'll learn how to find the perimeter of different shapes.

📚 What Is Perimeter?

The perimeter is the total distance around a shape. To find it, you add up the lengths of all the sides.

Think of a fence around a garden — the length of the fence is the perimeter!

📐 Finding Perimeter

Rectangle

A rectangle has 2 long sides (length L) and 2 short sides (width W).

Perimeter = 2L + 2W or P = 2(L + W)

Square

All 4 sides of a square are equal (side length S).

Perimeter = 4S or P = S + S + S + S

Triangle

Add up all 3 sides!

Perimeter = a + b + c

🎮 Let's Practice!

Example 1: A rectangle is 8 cm long and 3 cm wide. Perimeter?

P = 2(8) + 2(3) = 16 + 6 = 22 cm

Example 2: A square has sides of 5 inches. Perimeter?

P = 4 × 5 = 20 inches

Example 3: A triangle has sides of 6, 7, and 9 cm. Perimeter?

P = 6 + 7 + 9 = 22 cm

💡 Quick Tips

Perimeter is measured in regular units (not square units — that's area!)

For any shape, just add all the side lengths

Walking around the block = finding the perimeter!

📝 Practice Problems

A square has sides of 9 cm. What is its perimeter?

A rectangle is 12 m long and 5 m wide. Find its perimeter.

A triangle has sides of 4, 5, and 6 inches. What is its perimeter?

If a square's perimeter is 36 cm, how long is each side?

🎮 Play a Game!

Practice perimeter concepts with Swimming Otters — race and learn!