# CBSE Class 10 Maths Revision Notes Chapter 10

## Class 10 Mathematics Revision Notes for Circles of Chapter 10

Class 10 is considered one of the most important classes in a student’s life. It lays the foundation for the upcoming years. The marks acquired in the board examination decide the stream in which one will study. Therefore, it is important that every student must study properly in Class 10 to pursue their dreams and secure their future.

Mathematics is one of the most scoring subjects in the board examinations. Amongst all the chapters, Chapter 10 i.e. Circles is one of the most important topics that students should study properly to score well in the examination. To simplify the preparation part, it is very essential for students to study from NCERT Books and practice the questions to attain concept clarity.

Students should refer to the official website of Extramarks where they have provided Class 10 Mathematics Chapter 10 Notes. These notes have been created according to the CBSE syllabus and guidelines. Students can easily find them on the website and revise them thoroughly. They can even access other study material such as CBSE extra questions, CBSE sample papers, CBSE Previous Year Question Papers, important questions, etc.

## Access Class 10 Mathematics Chapter 10 – Circles

### Download Class 10 Mathematics Chapter 10 Circles Revision Notes – repeat

Topics Covered in Class 10 Mathematics Chapter 10 Circles

All the topics covered in Chapter 10 Mathematics Class 10 Notes are as per the CBSE syllabus. Students can access the entire list on the Extramarks website and start preparing for the examination. The topics are as given below:

• Tangent to a circle
• Number of tangents from a point of the circle
• Circle
• Center
• Chord
• Diameter

### Tangent to a Circle

A line that touches a circle exactly at one point is known as the tangent to a circle. For every point on a circle, there is a tangent passing through it.

Secant: A line that has two common points with a circle is known as a secant to a circle. It cuts the circle at two points forming a chord of a circle.

Tangent as a special case of Secant

The above diagram shows tangent as a special case of secant when two endpoints of its corresponding chord coincide.

Theorem 1: The tangent at any point of a circle is perpendicular to the radius through the point of contact.

Through the theorem one can conclude:

• For any point on a circle, there will be only one tangent.
• The line containing the radius through the point of contact is called normal to the circle at the point.

Theorem 2: The lengths of tangents drawn from an external point to a circle are equal.

### Number of Tangents from a Point on a Circle

• If there is a point in an inferior region of the circle then any line through that point will be a secant. So no tangent can be drawn to a circle that passes through the point that lies inside it.

• If the point of tangency lies on the circle there will be one tangent that can pass through it.

• If a point lies outside the circle, then there will be accurately two tangents to a circle through it.

### Circle Chapter Class 10 Notes: An Overview

Let us quickly have an overview of Chapter 10 Circles of Class 10 Mathematics.

### Circle:

When all the points in a definite plane are placed at a constant distance from each other to a fixed point it is known as a circle.

### Center:

A fixed point from which all other points in a plane are at the same distance is called the center.

Radius is defined as the fixed distance from which all the other points are at equal distance.

### Chord:

A line segment that can join two points on a circle is known as a chord.

Diameter:

The longest chord of the circle which passes through the center is known as the diameter.

### Tangent:

A line that meets the circle at one point or two lines coincides is known as a tangent. It is always perpendicular to the radius at the point of contact.

### Properties of Tangents drawn to a Circle

• Only one tangent is present at one point of contact in a circle.
• One cannot draw tangents at any point outside the circle.
• For any point present outside the circle only two tangents are present.

### Conclusion:

Through this chapter, you have studied the following points. They are as follows:

• The definition and meaning of the tangent of a circle.
• The tangent to a circle is perpendicular to the radius through the point of contact.
• The length of two tangents from an external point to a circle is equal.

### 1. Mention the maximum number of tangents that can be drawn from the external point to the circle.

One can draw a maximum of two tangents from the external point to the circle.

### 2. What is a tangent?

A tangent is a line that intersects the circle at any particular point.

### 3. How can I access the CBSE previous years’ question papers?

Students can visit the website of Extramarks to access the study materials such as previous years’ question papers, sample papers, revision notes including many more that can help them score well in board examinations.

### 4. Mention the key features of revision notes of Chapter 10 Circles.

All the revision notes are designed by the experts and contain information according to the CBSE guidelines. Simple language is used in the Class 10 notes that candidates can understand quickly, and therefore perform well in the examination.