Area and perimeter, made easy

Perimeter is the distance around a shape. Area is the space inside it. That's the whole difference!

Perimeter: walk around the edge

Add up the lengths of all the sides.

Area: count the squares inside

For a rectangle, multiply length × width. The answer is in square units, like cm².

Squares and triangles

• Square: all sides are equal. Area = side × side. Perimeter = 4 × side.
• Triangle: Area = 1/2 × base × height. A triangle is half of a rectangle, so it's half the area.

Try one yourself

Common mistakes

• Mixing them up. Perimeter = fence around a yard. Area = grass inside it.
• Forgetting "squared" units for area (cm², m²).
• Forgetting the 1/2 for triangles.