**Question 10:**

A technician needs to climb a ladder to repair a street lamp as shown in Diagram below.

(a) What is the length, in m, of the ladder?

(b) Find the height, in m, of the lamp post.

*Solution:*

(a)

(a)

$\begin{array}{l}\text{cos}{70}^{o}=\frac{1}{h}\\ h=\frac{1}{\text{cos}{70}^{o}}\\ h=\frac{1}{0.342}\\ h=2.924\text{m}\\ \\ \text{Hence,thelengthoftheladder}\\ =2.924\text{m}\end{array}$

**(b)**

$\begin{array}{l}\text{tan}{70}^{o}=\frac{T}{1}\\ T=\text{tan}{70}^{o}\times 1\\ \text{}=2.747\times 1\\ \text{}=2.747\text{m}\\ \\ \text{Theheightofthelamppost}\\ =2.747+1.2\\ =3.947\text{m}\end{array}$