# EXERCISE 8.3

**NCERT Solutions for Class 10 Maths Chapter 8 ( Introduction of Trigonometry)**

**NCERT Solutions for Class 10 Maths Chapter 8 ( Introduction of Trigonometry)**

**NCERT** Solutions for **Class 10 Maths** Chapter 8 Introduction of Trigonometry of** exercise 8.3 **for all boards. We have updated all the contents for the new academic session 2020-2021.

In this chapter, you have studied the following points:

- In a right triangle ABC, right-angled at B

- sin A=side opposite to angle A /hypotenuse
- cos A=side adjacent to angle A/hypotenuse
- tan A=side opposite to angle A/side adjacent to angle A

- cosec A=1/sin A; sec A=1/cos A; tan A=1/cot A; tan A=sin A/cos A;
- If one of the trigonometric ratios of an acute angle is known, the remaining trigonometric ratios of the angle can be easily determined.
- The values of trigonometric ratios for angles 0°, 30°, 45°, 60°, and 90°.
- The value of sin A or cos A never exceeds 1, whereas the value of sec A or cosec A is always greater than or equal to 1.
- sin (90° – A) = cos A, cos (90° – A) = sin A;

tan (90° – A) = cot A, cot (90° – A) = tan A;

sec (90° – A) = cosec A, cosec (90° – A) = sec A.