# CBSE Class 10-Mathematics: Chapter –8 Introduction to Trigonometry Part 6

Get top class preparation for CBSE right from your home: fully solved questions with step-by-step explanation- practice your way to success.

**Question 10:**

If , prove that .

**Answer:**

Given:

**Question11:**

If , where is an acute angle, find the value of A.

**Answer:**

Given:

**Question12:**

If A, B and C are interior angles of a , then show that

**Answer:**

Given: A, B and C are interior angles of a.

**Question13:**

Express in terms of trigonometric ratios of angles between and

**Answer:**

**Question14:**

Express the trigonometric ratios and in terms of .

**Answer:**

For ,

By using identity

For

By using identity

For