Question

pls answer 38 and 39​

Answer 1

Answer:

Step-by-step explanation:

Answer 2

Answer:

Step-by-step explanation:

Consider the height of the tower $AB=x\text{ m}$

The distance between the tower and point C is $BC=4\text{ m}$

The distance between the tower and point D is $BD=9\text{ m}$

As the angle of elevation of the top of the tower from two points are complementary. then the sum of two angles are 90 degree.

consider, $\angle ACB=\theta$ therefore $\angle ADB=(90-\theta)$

In $\Delta ACB,$

$\frac{AB}{BC}=\tan\theta\\\\\Rightarrow\frac{x}{4}=\tan\theta\text{..................equation-1}$

In $\Delta ADB,$

$\frac{AB}{BD}=\tan(90-\theta)\\\\\Rightarrow\frac{x}{9}=\tan(90-\theta)\\\\\Rightarrow\frac{x}{9}=\cot\theta\text{ }[\tan(90-\theta)=\cot\theta]\\\\\Rightarrow\frac{x}{9}=\frac{1}{\tan\theta}\\\\\Rightarrow\frac{x}{9}=\frac{1}{\frac{x}{4}}\text{ [put the value of}\tan\theta\text{ from equation-1]}\\\\\Rightarrow\frac{x}{9}={\frac{4}{x}}\\\\\Rightarrow{x}^{2}=36\\\\\Rightarrow{x}=6\text{ m}$