NCERT Class 3 Maths (Maths Mela) · Chapter 5
Fun with Shapes
Rectangles, squares, triangles, and circles: sides, corners, square corners, and fun activities with rangoli, matchsticks, and tangrams.
📌 What you’ll learn in this chapter
- Flat shapes: rectangle, square, triangle, circle
- Counting sides and corners
- How a square is different from a rectangle
- Square corners (like the corner of a book)
- The centre of a circle, and fun with matchsticks and tangrams
🌸 Let’s Begin: Rangoli Shapes
On Diwali morning, Meenu helped Amma make a rangoli. Amma drew a big square, a circle inside it, and triangles on the corners like petals. “Every rangoli is made of simple shapes!” said Amma.
⬜ Part 1: Know Your Shapes
| Shape | Sides | Corners | Special thing |
|---|---|---|---|
| Rectangle | 4 | 4 square corners | Opposite sides are equal |
| Square | 4 | 4 square corners | All 4 sides are equal |
| Triangle | 3 | 3 | Can have many shapes |
| Circle | No straight sides | 0 | Round, with a centre |
💡 Square vs rectangle
A square is a special rectangle where all 4 sides are equal. A ludo board is a square, and a door is a rectangle.
📐 Part 2: Square Corners
The corner of a book, a door, or a blackboard is a square corner. Fold a paper twice to make a “corner checker” and test corners around you!
- Some corners are less than a square corner (pointy, like a slice of pizza).
- Some corners are more than a square corner (wide open, like a fan’s blades).
⭕ Part 3: Circles
Fold a paper plate in half one way, then in half another way. The two fold lines cross at the centre of the circle. Every fold through the centre is the longest line across the circle.
📦 Part 4: Opening a Box
Open a toothpaste or sweet box carefully and flatten it. You’ll see 6 faces, which are rectangles (and sometimes squares). A matchbox gives 3 different rectangles (each appears twice).
⚠️ Common mistake
Thinking a tilted square is a “diamond” and not a square. Turning a shape doesn’t change it. A square is still a square!
✏️ Practice Time
Try these on your own first, then check your answer below each question.
Q1. How many sides and corners does a triangle have?
✅ Answer3 sides and 3 corners
Q2. Name 3 things that have rectangular faces.
✅ AnswerFor example, a book, a door, a mobile phone, or a brick.
Q3. Is every square a rectangle?
✅ AnswerYes. It has 4 square corners and equal opposite sides.
Q4. Name 2 round things.
✅ AnswerFor example, a bangle, a coin, a clock, or a roti.
📘 NCERT Textbook Activity Help
Hints and answers for the activities in the textbook, page by page. Try each one yourself before looking at the answer!
Pages 44–45 · Amma’s rangoliShapes in rangoli
✅ AnswerThe rangoli uses circles, squares, and triangles (and petal shapes). Count the shapes made with curved lines (circles and petals) and those made with straight lines (squares and triangles) in your book.
Pages 46–48 · Boxes and facesOpening boxes
✅ AnswerA flattened box shows rectangles (and sometimes squares). The two children traced different boxes: a matchbox has 3 different rectangles, and the wooden box had a square face and rectangular faces. Objects with rectangular faces: book, brick, duster.
Tracing a cuboid (eraser): (a) usually 3 different faces (each appears twice) (b) rectangles (c) only if the cuboid has square ends (d) No, opposite faces are the same, so there are at most 3 different ones (e) No (f) rectangle or square
Pages 49–50 · RectanglesTracing a cuboid (eraser): (a) usually 3 different faces (each appears twice) (b) rectangles (c) only if the cuboid has square ends (d) No, opposite faces are the same, so there are at most 3 different ones (e) No (f) rectangle or square
Draw and count
✅ AnswerA rectangle has (a) 4 sides (b) 4 corners (c) Yes, opposite sides are equal (d) All the corners are square corners, and the opposite sides are equal. For the counting picture, count the small rectangles and also the bigger ones made by joining them.
Pages 51–53 · SquaresSame to same
✅ AnswerBoth have 4 sides and 4 corners. In the drawing, count the small squares and also the bigger squares made from them.
Joining squares: 2 squares → 1 shape · 3 squares → 2 shapes (a line and an L) · 4 squares → 5 shapes (a line, square, L, T, and zig-zag).
Rectangles: shapes with 4 square corners and equal opposite sides are rectangles. Shapes with slanting sides or curves are not.
Pages 54–56 · Square corners and matchsticksJoining squares: 2 squares → 1 shape · 3 squares → 2 shapes (a line and an L) · 4 squares → 5 shapes (a line, square, L, T, and zig-zag).
Rectangles: shapes with 4 square corners and equal opposite sides are rectangles. Shapes with slanting sides or curves are not.
Corners and squares
✅ AnswerYes, all the corners of a square are the same (they match when you pile them up), and so are the corners of a rectangle. They are all square corners. Objects with square corners: book, blackboard, door, table top.
Two matchsticks crossing each other in a plus (+) shape make 4 square corners.
12 matchsticks: make a 2 × 2 grid to get 5 squares (4 small + 1 big).
Page 57 · TrianglesTwo matchsticks crossing each other in a plus (+) shape make 4 square corners.
12 matchsticks: make a 2 × 2 grid to get 5 squares (4 small + 1 big).
Counting triangles
✅ AnswerTriangles have 3 sides and 3 corners. Triangular objects: a samosa, a road sign, a slice of watermelon. In the rangoli, count the small triangles and also the bigger triangles made from them. Matchstick puzzle: move two sticks to make a line across the middle, so there are two triangles.
Pages 58–63 · Circles and moreCircles, patterns, and tangram
✅ AnswerRound objects: bangle, coin, wheel, plate, clock. A circle has no corners and no straight sides. The fold lines meet at the centre.
Square and triangle: both have straight edges. Their corners and number of sides are different.
Triangle rows: the second figure has 4 small triangles (5 if you count the big one), and the third has 9 small triangles.
Tangram: try the pieces in different ways. The big triangles often go at the edges.
Square and triangle: both have straight edges. Their corners and number of sides are different.
Triangle rows: the second figure has 4 small triangles (5 if you count the big one), and the third has 9 small triangles.
Tangram: try the pieces in different ways. The big triangles often go at the edges.
👨👩👧 Tips for Parents
- Draw a rangoli together and name the shapes.
- Make shapes with matchsticks or ice-cream sticks.
- Fold paper to make a square-corner checker and test corners around the house.