Learn about the geometry of circles with our easy to follow explanation. Learn about the center, radius, and diameter to deepen your understanding of this fundamental shape. Ideal for students, educators, and math enthusiasts
Hey there, parents and young learners! Ready to dive into the super cool world of circles? A video is made just for Class 4 kids and it’s packed with fun and easy-to-get stuff all about circles in Geometry.
Why Practice Makes Perfect ?
If you enjoyed these questions and want to practice more, we have a fantastic resource for you. Our Maths Practice Workbooks have more questions on circles and other geometry topics. These workbooks will help you master the concepts you’ve learned today. After reading this blog and watching the video, you’ll be able to solve these worksheets on your own. No more fear of maths or geometry!
So there you go, an exciting journey through the world of circles! Keep practicing, and you’ll be a geometry genius in no time.
Geometry for Class 4 worksheets
Geometry for Class 5 worksheets
What is a circle?
A circle is simple and closed figure made up of curved line.
Does circle have straight lines?
NO, It is made up of curved line only.
Is circle a polygon?
Since polygon is made up of straight lines whereas a circle is made up of only curved lines, it’s correct to say that a circle is not a polygon.
What is the definition of a circle?
A circle is a simple closed curve in which all points on it are at the same distance from a fixed point.
Define Centre of a circle.
WHAT IS CENTRE OF A CIRCLE ?
The fixed point mentioned in the definition of the circle is called the centre of a circle.
What is radius of a circle?
The fixed distance mentioned above in the definition of circle is called the radius.
How many radii are there in a circle?
Radii is plural of radius. When we talk about more than one radius we call it radii. There are infinitely many radii in a circle.
What is chord of a circle?
A line segment obtained by joining any two points on a crick are called chord off a circle.
What is Diameter of a circle?
A chord of a circle which passes through the centre of a circle is called the diameter of the circle.
How can we find radius when diameter is known and vice-versa?
Firstly , radius is smaller in value than diameter. Radius is half of a diameter whereas diameter is double the radius.
Radius = diameter ÷ 2
Diameter = 2 × radius
Finding the Radius When Diameter is Known
Question:
The diameter of a circle is 10 cm. What is the radius of the circle?
Solution:
To find the radius, we use the formula:
Radius = Diameter ÷ 2
Substitute in the given diameter:
Radius = 10 cm ÷ 2
Radius = 5 cm
So, the radius of the circle is 5 cm.
Finding the Diameter When Radius is Known
Question:
The radius of a circle is 7 cm. What is the diameter of the circle?
Solution:
To find the diameter, we use the formula:
Diameter = 2 × Radius
Substituting in the given radius:
Diameter = 2 × 7 cm
Diameter = 14 cm
So, the diameter of the circle is 14 cm.
Finding the Radius When Diameter is Known
Question:
The diameter of a circle is 16 cm. What is the radius of the circle?
Solution:
To find the radius, we use the formula:
Radius=Diameter÷2
Substituting in the given diameter:
Radius=16 cm÷2
Radius=8 cm
So, the radius of the circle is 8 cm.
Practice Questions
Question 1:
What is the radius of a circle if its diameter is 20 cm?
Question 2:
The diameter of a circle is 12 cm. Can you find its radius?
Question 3:
If the radius of a circle is 9 cm, what would be its diameter?
Question 4:
A circle has a radius of 15 cm. Calculate its diameter.
Question 5:
Find the radius of a circle with a diameter of 18 cm.
Question 6:
The diameter of a circle is 22 cm. What is its radius?
Question 7:
If the radius of a circle is 5 cm, what is its diameter?
Question 8:
A circle has a diameter of 30 cm. What is its radius?
Answers to Practice Questions
Answer 1:
Radius = 20 cm ÷ 2 = 10 cm
Answer 2:
Radius = 12 cm ÷ 2 = 6 cm
Answer 3:
Diameter = 2 × 9 cm = 18 cm
Answer 4:
Diameter = 2 × 15 cm = 30 cm
Answer 5:
Radius = 18 cm 2 = 9 cm
Answer 6:
Radius = 22 cm ÷ 2 = 11 cm
Answer 7:
Diameter = 2 × 5 cm = 10 cm
Answer 8:
Radius = 30 cm ÷ 2 = 15 cm
Time to Practice! Get your pencils ready, young mathematicians! We’ve got more questions for you to solve.
Circle Facts quiz. State True or False
- here is only one centre in a circle. TRUE
- Different chords may have different lengths. TRUE
- Lengths of radius is half the length of diameter. TRUE
- A circle has many diameter. TRUE
- There are many radii in a circle. TRUE
- Diameter of a circle is the longest chord. TRUE
- All diameters have same length. TRUE
Multiple Choice Questions:
What is the term for the distance from the centre of the circle to its edge?
a) Diameter
b) Radius
c) Chord
Answer: b) Radius
Which of the following passes through the centre of the circle?
a) Radius
b) Diameter
c) Both
Answer: a) Both
What is twice as long as the radius?
a) Diameter
b) Chord
c) Centre
Answer: a) Diameter
A segment whose endpoints are on a circle is called a ____.
a) Diameter
b) Radius
c) Chord
Answer: c) Chord
True or False
The diameter is twice the radius.
Answer: True
All chords pass through the centre of the circle.
Answer: False
The radius and diameter are the same things.
Answer: False
All radii in a circle have different lengths.
Answer: False
One-Word Answers:
What do you call a line segment that touches two points on the circle but doesn’t pass through the centre?
Answer: Chord
What is the exact middle point of the circle called?
Answer: Centre
What is the line that cuts the circle into two equal halves called?
Answer: Diameter
Fill-in-the-Blanks:
The ________ is the point right in the middle of the circle.
Answer: Centre
A line segment from one edge of the circle to another that passes through the centre is called the ________.
Answer: Diameter
The ________ is a line from the centre of the circle to any point on its circumference.
Answer: Radius
Here’s What We’ll Cover in this video :
- What Is a Circle? Let’s get the basics down!
- Center and Radius: The main parts you gotta know.
- What’s a Chord? We’ll show you.
- Finding Radius and Diameter: We make it easy-peasy.
- Fun Circle Facts: Bet you didn’t know these!
- Circle Properties: Quick stuff you should know.
- True or False: How much do you really know?
- Fill in the Blanks: A fun way to learn more.
- Practice Time: Get those brains working!
By the end of this video, your kiddo will totally get what circles are all about. So go ahead, click “Play” and let’s start the fun learning adventure!