Chapter 8, Problem 13CR

To determine

To find : the value of x in the figure

Answer to Problem 13CR

The value of x is $x=8.66$

Explanation of Solution

Given Information: A right angled triangle with an acute angle of 30⁰ with adjacent side and hypotenuse as x and 10 respectively.

Formula used:

In a right triangle, the cosine of the angle is the ratio of the adjacent side of the angle to the hypotenuse.

  

It can be expressed as,

  $\cos B=\frac{b}{c}$

Calculation: Consider the right triangle given below.

  

Here, with reference to the definition of cosine of an angle and for the given figure,

  $\begin{array}{c}\cos 30°=\frac{x}{10}\\ x=10\cos 30°\\ =8.66\end{array}$