⭕ Circles, Corners and Shapes
Class 4 Maths · Unit 6 of 12 · about 120 minutes
This unit introduces the basic parts of a circle (centre, radius, diameter) and the concept of right angles as square corners. Children learn to identify right angles, compare angles as more or less than a right angle, and explore how shapes tile a flat surface. This foundational geometry supports later work on symmetry, perimeter, and area.
What your child will learn
- Students will be able to identify the centre, radius, and diameter of a circle.
- Students will be able to identify right angles in objects and shapes.
- Students will be able to classify angles as right, more than right, or less than right.
- Students will be able to explore which shapes tile a flat surface without gaps or overlaps.
Lessons in this unit
- Parts of a Circle: Introduce the circle and its parts: centre, radius, diameter. Use a real object like a bangle or a coin to draw a circle and mark the parts.
- Right Angles: Introduce right angles as square corners. Use a corner of a paper or a set square to check if an angle is right.
- More or Less than a Right Angle: Compare angles to a right angle: less than (acute) or more than (obtuse). Use a paper corner as a reference.
- Tiling with Shapes: Explore which shapes can tile a flat surface without gaps or overlaps. Use squares, triangles, rectangles, and circles.
Key words
- circle
- A round shape where every point on the edge is the same distance from the centre.
- centre
- The exact middle point of a circle.
- radius
- A line from the centre of a circle to any point on the edge.
- diameter
- A line that goes through the centre from one edge to the other. It is twice the radius.
- right angle
- A corner like the corner of a square or a book. It makes an L shape.
- tiling
- Covering a flat surface with shapes that fit together without gaps or overlaps.
Help your child at home
What to watch for
- Any line from one edge to another is a diameter.
- Help: Show a chord that is not through the centre and explain it is not a diameter.
- Any corner is a right angle.
- Help: Show a corner that is not a right angle (e.g., a slice of pizza) and compare with a paper corner.
- A bigger angle is always more than a right angle.
- Help: Show two angles with the same opening but different line lengths.
- Circles can tile because they can be placed next to each other.
- Help: Show a picture of circles side by side and highlight the gaps.
Try this at home
- Name the parts of a circle drawn round a bangle: the centre is the middle point, a radius goes from the centre to the edge, a diameter goes edge to edge through the centre
- Identify which corners of a shape are right angles
- Hold a paper corner on each angle: if the angle fits inside the corner it is less than right; if it opens wider it is more than right
- Predict if a shape tiles, then verify with cut-outs
Quick questions to ask aloud
- Point A is on the edge of a circle, point B is in the exact middle, and point C is outside the circle. Which point is the centre? (A / B / C)
Show answer
The centre is the exact middle point of the circle. Point B is in the middle. - True or false: The corner of a door is smaller than a right angle.
Show answer
False. A door corner is a square corner, so it is exactly a right angle. - Which angle is less than a right angle? (🍕 Pizza slice corner / 📕 Book corner / 🚪 Door opened wide)
Show answer
🍕 Pizza slice corner. A pizza slice corner is smaller than a right angle, so it is less than right.
Frequently asked questions
What will my child learn in "Circles, Corners and Shapes" (Class 4 Maths)?
Your child will be able to: identify the centre, radius, and diameter of a circle.; identify right angles in objects and shapes.; classify angles as right, more than right, or less than right.; explore which shapes tile a flat surface without gaps or overlaps..
How does MangoMindz teach "Circles, Corners and Shapes"?
In 4 short parts (Parts of a Circle, Right Angles, More or Less than a Right Angle, Tiling with Shapes). Each part has a picture-based lesson read aloud by Mango Teacher, a quick check, and a quiz built from common mistakes children make, with Mango, a study buddy, for questions.
How long does "Circles, Corners and Shapes" take?
About 120 minutes in total, spread over 4 parts of 15–25 minutes each.
How can I help my child with "Circles, Corners and Shapes" at home?
Work through a small example together, such as: Name the parts of a circle drawn round a bangle: the centre is the middle point, a radius goes from the centre to the edge, a diameter goes edge to edge through the centre; Identify which corners of a shape are right angles. Then ask a quick question aloud: Point A is on the edge of a circle, point B is in the exact middle, and point C is outside the circle. Which point is the centre? (A / B / C)
What mistakes do children often make in "Circles, Corners and Shapes"?
Any line from one edge to another is a diameter. Fix: Show a chord that is not through the centre and explain it is not a diameter. Any corner is a right angle. Fix: Show a corner that is not a right angle (e.g., a slice of pizza) and compare with a paper corner. A bigger angle is always more than a right angle. Fix: Show two angles with the same opening but different line lengths.
Is "Circles, Corners and Shapes" free on MangoMindz?
Yes. Every lesson part and quiz in "Circles, Corners and Shapes" is free on MangoMindz, with no ads.