Question

An electrician leans an extension ladder against the outside wall of a

house so that it reaches an electric box 28 feet up. The ladder makes an
angle of 71° with the ground. Find the length of the ladder. Round your
answer to the nearest hundredth of a foot if necessary.

Answer 1

30 feet

Explanation:

i used a ruler, mm side. 1 mm = 1 foot

draw a horizontal line.

draw a vertical line 28mm high

use a protractor to find a line that connects to the base and top of vertical line.

measure said line

Answer 2

Explanation:

\text{sin }\color{purple}{71}=\frac{\color{green}{\text{opposite}}}{\color{#EB0000}{\text{hypotenuse}}}=\frac{\color{green}{28}}{\color{#EB0000}{x}}

sin 71=

hypotenuse

opposite

​

=

x

28

​

\text{sin }71=

sin 71=

\,\,\frac{28}{x}

x

28

​

\frac{\text{sin }71}{1}=

1

sin 71

​

=

\,\,\frac{28}{x}

x

28

​

x\text{ sin }71=

x sin 71=

\,\,28

28

Cross multiply.

\frac{x\text{ sin }71}{\text{ sin }71}=

sin 71

x sin 71

​

=

\,\,\frac{28}{\text{ sin }71}

sin 71

28

​

Divide both sides by sin 71

x=\frac{28}{\text{ sin }71}=29.613379...\approx29.61

x=

sin 71

28

​

=29.613379...≈29.61