# NCERT Solutions for Class 10 Maths Chapter 8 Introduction to Trigonometry

NCERT Solutions for Class 10 Maths Chapter 8 Introduction to Trigonometry-

This chapter introduces the concept of trigonometry. We will study some ratios of a right-angled triangle with respect to its acute angles, and this ratio called trigonometric ratios of the angles. Unit 5 "Trigonometry" holds 12 marks out of 80 marks in the maths paper of class 10 CBSE exam. And we can expect 2-3 question from this chapter of total around 8 marks. This chapter contain4 exercises with 27 questions. The NCERT Solutions for Class 10 Maths Chapter 8 Introduction to Trigonometry are solved by our subject experts to help students in their preparation of CBSE Class 10 Board exam. These NCERT solutions are the detailed explanation of each question of class 10 NCERT maths textbook.

In all the situations where the right angle triangle can be imagined, the heights or distances can be found by using some mathematical approach, which comes under a branch of mathematics called ‘trigonometry’. The trigonometry is the study of relationships between angles and the sides of a triangle. The NCERT Class 10 Maths Chapter 8 Introduction to Trigonometry also defines the trigonometric ratios for angles of measure $0^o$and $90^o$. We will also learn how to calculate the trigonometric identities and solve some specific angles of the trigonometric ratios cosine, sine, tangents etc. If any trigonometric ratio of an acute angle is known, the remaining trigonometric ratios of an angle can be easily determined.

The trigonometric ratios of the angle A in right triangle ABC are defined as follows-

$\dpi{100} \\sine \:of\: \angle A=\frac{side \:opposite \:to \:angle \:A}{hypotenuse}=\frac{BC}{AC}\\\\cosine \:of\: \angle A=\frac{side \:adjacent\: to \:angle \:A}{hypotenuse}=\frac{AB}{AC}\\\\tangent \:of\: \angle A=\frac{side \:opposite \:to \:angle \:A}{side \:adjacent\: to \:angle \:A}=\frac{BC}{AB}\\\\cosecant \:of\:\angle A=\frac{hypotenuse}{side \:opposite \:to \:angle \:A}=\frac{AC}{BC}\\\\secant \:of \:\angle A= \frac{hypotenuse}{side \:adjacent\: to \:angle \:A}=\frac{AC}{AB}\\\\cotangent \:of\: \angle A=\frac{side \:adjacent\: to \:angle \:A}{side \:opposite \:to \:angle \:A}=\frac{AB}{BC}$

The values of all the trigonometric ratios of 0°, 30°, 45°, 60°, and 90° are-

 $\dpi{100} \angle A$ $\dpi{100} 0^o$ $\dpi{100} 30^o$ $\dpi{100} 45^o$ $\dpi{100} 60^o$ $\dpi{100} 90^o$ Sin A 0 $\dpi{100} \frac{1}{2}$ $\dpi{100} \frac{1}{\sqrt{2}}$ $\dpi{100} \frac{\sqrt{3}}{2}$ 1 Cos A 1 $\dpi{100} \frac{\sqrt{3}}{2}$ $\dpi{100} \frac{1}{\sqrt{2}}$ $\dpi{100} \frac{1}{2}$ 0 Tan A 0 $\dpi{100} \frac{1}{\sqrt{3}}$ 1 $\dpi{100} \sqrt{3}$ Not defined Cosec A Not defined 2 $\dpi{100} \sqrt{2}$ $\dpi{100} \frac{2}{\sqrt{3}}$ 1 Sec A 1 $\dpi{100} \frac{2}{\sqrt{3}}$ $\dpi{100} \sqrt{2}$ 2 Not defined Cot A Not defined $\dpi{100} \sqrt{3}$ 1 $\dpi{100} \frac{1}{\sqrt{3}}$ 0

## 8.1 Introduction

8.2 Trigonometric Ratios

8.3 Trigonometric Ratios of Some Specific Angles

8.4 Trigonometric Ratios of Complementary Angles

8.5 Trigonometric Identities

8.6 Summary

## NCERT Solutions for Class 10 Maths Chapter  8 Introduction to Trigonometry - Exercise 8.1

NCERT Solutions for Class 10 Maths Chapter  8 Introduction to Trigonometry - Exercise 8.2

NCERT Solutions for Class 10 Maths Chapter  8 Introduction to Trigonometry - Exercise 8.3

NCERT Solutions for Class 10 Maths Chapter  8 Introduction to Trigonometry - Exercise 8.4

## NCERT Solutions for Class 10 Maths - Chapter-wise

 Chapter No. Chapter Name Chapter 1 Real Numbers Chapter 2 Polynomials Chapter 3 Pair of Linear Equations in Two Variables Chapter 4 Quadratic Equations Chapter 5 Arithmetic Progressions Chapter 6 Triangles Chapter 7 Coordinate Geometry Chapter 9 Some Applications of Trigonometry Chapter 10 Circles Chapter 11 Constructions Chapter 12 Areas Related to Circles Chapter 13 Surface Areas and Volumes Chapter 14 Statistics Chapter 15 Probability

## NCERT Solutions for Class 10 - Subject Wise

 NCERT Solutions for Class 10 Maths NCERT Solutions for Class 10 Science