A right triangle has one angle that measures [tex]$23^{\circ}$[/tex]. The adjacent leg measures [tex]$27.6 \, \text{cm}$[/tex] and the hypotenuse measures [tex]$30 \, \text{cm}$[/tex].

What is the approximate area of the triangle? Round to the nearest tenth.

Area of a triangle [tex]$= \frac{1}{2} b h$[/tex]

[tex]\[
\begin{array}{l}
A. \, 68.7 \, \text{cm}^2 \\
B. \, 161.8 \, \text{cm}^2 \\
C. \, 381.3 \, \text{cm}^2 \\
D. \, 450.0 \, \text{cm}^2
\end{array}
\][/tex]



Answer :

To find the approximate area of the right triangle, we can follow these steps:

1. Understand the given values:
- Adjacent side (base): \( 27.6 \, \text{cm} \)
- Hypotenuse: \( 30 \, \text{cm} \)
- One angle (besides the right angle): \( 23^\circ \)

2. Find the length of the opposite side:
- Using the trigonometric function sine, we know that \( \sin(\theta) = \frac{\text{opposite}}{\text{hypotenuse}} \).
- Here, \( \theta = 23^\circ \).

Thus,
[tex]\[ \sin(23^\circ) = \frac{\text{opposite}}{30} \][/tex]

Solving for the opposite side:
[tex]\[ \text{opposite} = 30 \times \sin(23^\circ) \][/tex]

Using the result:
[tex]\[ \text{opposite} \approx 11.72 \, \text{cm} \][/tex]

3. Calculate the area of the triangle:
- The formula for the area of a triangle is:
[tex]\[ \text{Area} = \frac{1}{2} \times \text{base} \times \text{height} \][/tex]
- In this case, the base is the adjacent side, \( 27.6 \, \text{cm} \), and the height is the opposite side we calculated, \( 11.72 \, \text{cm} \).

Substituting the values:
[tex]\[ \text{Area} = \frac{1}{2} \times 27.6 \times 11.72 \][/tex]

Performing the multiplication:
[tex]\[ \text{Area} \approx 161.76 \, \text{cm}^2 \][/tex]

4. Round to the nearest tenth:
[tex]\[ \text{Area} \approx 161.8 \, \text{cm}^2 \][/tex]

Therefore, the approximate area of the triangle is [tex]\( \boxed{161.8 \, \text{cm}^2} \)[/tex]. This matches the provided result and confirms our calculations. Hence, the correct answer is [tex]\( 161.8 \, \text{cm}^2 \)[/tex].

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