Question

8
40°
10 ft
x = ft

Explanation:

Step1: Use cosine function

In a right - triangle, $\cos\theta=\frac{\text{adjacent}}{\text{hypotenuse}}$. Here, $\theta = 40^{\circ}$, adjacent side $= 10$ ft and hypotenuse $=x$. So, $\cos40^{\circ}=\frac{10}{x}$.

Step2: Solve for \(x\)

We can rewrite the equation as $x=\frac{10}{\cos40^{\circ}}$. Using a calculator, $\cos40^{\circ}\approx0.7660$. Then $x=\frac{10}{0.7660}\approx13.05$.

Answer:

$13.05$