Hi shiva,

Since you have not mentioned your class and board, I am unable to draw appropriate details from your query. However, If you are referring to recent update in syllabus by CBSE then, for 10th class students following topics is reduced in  mathematics syllabus from various chapters.

UNIT I-NUMBER SYSTEMS

• REAL NUMBERS - Euclid’s division lemma

UNIT II-ALGEBRA

• POLYNOMIALS- Statement and simple problems on division algorithm for polynomials with real coefficients.
• PAIR OF LINEAR EQUATIONS IN TWO VARIABLES - cross multiplication method
• QUADRATIC EQUATIONS - Situational problems based on equations reducible to quadratic equations
• ARITHMETIC PROGRESSIONS - Application in solving daily life problems based on sum to n terms

UNIT III-COORDINATE GEOMETRY

• COORDINATE GEOMETRY - Area of a triangle

UNIT IV-GEOMETRY

• TRIANGLES- Proof of the following theorems are deleted  ,  The ratio of the areas of two similar triangles is equal to the ratio of the squares of their corresponding sides.  In a triangle, if the square on one side is equal to sumof the squares on the other two sides, the angle opposite to the first side is a right angle
• CONSTRUCTIONS - Construction of a triangle similar to a given triangle.

UNIT V- TRIGONOMETRY

• INTRODUCTION TO TRIGONOMETRY- Motivate the ratios whichever are defined at 0o and 90o
• TRIGONOMETRIC IDENTITIES- Trigonometric ratios of complementary angles

UNIT VI-MENSURATION

• AREAS RELATED TO CIRCLES- Problems on central angle of 120°
• SURFACE AREAS AND VOLUMES- Frustum of a cone

UNIT VI-STATISTICS & PROBABILITY

• STATISTICS- · Step deviation Method for finding the mean  ;· Cumulative Frequency graph

Also CBSE is expected to follow certain changes in the Maths question paper structure amounting to 25% objective questions  in the board exam.

Refer to following link for more details:

http://cbseacademic.nic.in/web_material/CurriculumMain21/Main-Secondary/Mathematics_Sec_2020-21.pdf

Good Luck