You are building a ramp that must cover a horizontal distance of exactly 29 feet. The angle of the ramp from the ground is 30 degrees. Determine the length of the ramp, in feet.

Respuesta :

The ramp forms a right triangle like this one:

Where L is the length of the ramp. As you can see L is the hypotenuse of the right triangle and the 29 ft horizontal distance is one of its legs. Here we can use the definition of the cosine of an angle in a right triangle:

[tex]\cos x=\frac{\text{adjacent side}}{\text{hypotenuse}}[/tex]

Then for the 30° angle we have:

[tex]\cos 30^{\circ}=\frac{29ft}{L}[/tex]

We can multiply both sides of this equation by L and divide by cos30°:

[tex]\begin{gathered} \cos 30^{\circ}\cdot\frac{L}{\cos30^{\circ}}=\frac{29ft}{L}\cdot\frac{L}{\cos30^{\circ}} \\ L=\frac{29ft}{\cos30^{\circ}} \end{gathered}[/tex]

And since:

[tex]\cos 30^{\circ}=\frac{\sqrt[]{3}}{2}[/tex]

We get:

[tex]L=\frac{29ft}{\cos30^{\circ}}=\frac{29ft}{\frac{\sqrt[]{3}}{2}}=\frac{2\cdot29ft}{\sqrt[]{3}}\approx33.49ft[/tex]

Then the answer is 33.49ft.

Ver imagen ChristinI653562