How do I remember all the formulas for different shapes?

In one line

The rule

Each geometric shape (like square, rectangle, circle, triangle) has its own formulas for area, perimeter, and volume. These formulas tell you how much space is inside (area/volume) or around (perimeter) the shape.

Let's understand it simply

Imagine you are rolling out roti in the kitchen. The round roti has a size (area) and the edge (perimeter). If you know the formula, you can quickly tell how much dough you need or how long the edge is. Each shape—like a cricket field (circle), a football ground (rectangle), or a classroom (rectangle)—has its own way to measure area and perimeter. If you see these shapes in daily life, the formulas will make more sense.

How it works

1. Look for patterns: Many formulas are similar. For example, the area of a rectangle is length × breadth. The area of a square is side × side (which is just a rectangle with equal sides).
2. Use mnemonics (memory tricks): For example, "All Parrots Like Bananas" can remind you: Area = Perimeter × Length for a rectangle (though the real formula is Area = Length × Breadth).
3. Connect to real objects: Think of a circle as a chapati, a rectangle as your maths book, a triangle as a slice of bread.
4. Practice drawing and labelling: Draw the shape, write the formula next to it, and label the sides. This helps your brain remember.

The story behind it

Mathematicians from ancient times, including those from India, Egypt, and Greece, wanted to measure land, build houses, and store grain. They found these formulas by cutting shapes, measuring, and looking for patterns. For example, Aryabhata, an Indian mathematician, worked on the area of circles and triangles over 1,500 years ago.

Where you see it in real life

• Cricket field (circle): To find the area to water or mow → use area of a circle formula.
• Classroom floor (rectangle): To buy tiles → use area of rectangle.
• Football goal post (rectangle): To paint the border → use perimeter of rectangle.
• Diwali rocket box (cuboid): To find how much space it takes → use volume of cuboid.
• Village well (cylinder): To find water volume → use volume of cylinder.
• Roti (circle): To know how big it is → use area of circle.

Why it matters

• Used in building houses, roads, and playgrounds.
• Needed for buying paint, tiles, or fencing.
• Important for exams and higher studies in maths, physics, and engineering.
• Helps in daily life—like cooking, shopping, or farming.

Common mistakes

• Mixing up area and perimeter (area is inside, perimeter is the boundary).
• Forgetting to use the right units (cm² for area, cm for perimeter).
• Using the wrong formula for the shape (using rectangle formula for a triangle).
• Not squaring or cubing the units for area or volume.

Remember it

Try this: Draw each shape, write the formula inside it, and say it out loud. For circles, remember: "Pie are square" (πr²) — sounds funny, but it works!

Worked example

Let's find the area and perimeter of a rectangle with length 8 m and breadth 5 m.

Given: length = 8 m, breadth = 5 m
Step 1: Area = length × breadth = 8 × 5 = 40 m²
Step 2: Perimeter = 2 × (length + breadth) = 2 × (8 + 5) = 2 × 13 = 26 m