A tent pole, of length 229 cm, stands perpendicular to the ground. A straight support rod connects the top of the tent pole to a point on the ground. The angle between the support rod and the ground is 65°. Calculate the length of the support rod. Give your answer in centimetres to the nearest integer.​



Answer :

To find the length of the support rod connecting the top of the tent pole to the ground, we can use trigonometry, specifically the sine function.

Given:

- Length of the tent pole (height perpendicular to the ground) = 229 cm

- Angle between the support rod and the ground = 65°

We need to find the length \( L \) of the support rod.

Using the sine function:

\[ \sin(\theta) = \frac{\text{opposite}}{\text{hypotenuse}} \]

In this case, the opposite side to the angle of 65° is the length of the tent pole (229 cm), and the hypotenuse is the length of the support rod \( L \).

So,

\[ \sin(65^\circ) = \frac{229}{L} \]

To find \( L \), rearrange the equation:

\[ L = \frac{229}{\sin(65^\circ)} \]

Now, calculate \( L \):

\[ L = \frac{229}{\sin(65^\circ)} \]

Using a calculator:

\[ \sin(65^\circ) \approx 0.9063 \]

Therefore,

\[ L = \frac{229}{0.9063} \approx 252.70 \]

Rounded to the nearest integer, the length of the support rod \( L \) is approximately \( \boxed{253} \) centimetres.

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