A triangle with three sides labeled as 25 centimeters, 24 centimeters, and 19 centimeters is shown. The angle opposite the side labeled 24 centimeters is labeled x degrees.

Question
Use the image to answer the question.
Solve for x in the triangle.
(1 point)
Responses

25.6
25.6

27.8
27.8

45.6
45.6

64.4

1 answer

To solve for angle \( x \) in the triangle using the given side lengths, we can apply the Law of Cosines. The Law of Cosines states:

\[ c^2 = a^2 + b^2 - 2ab \cdot \cos(C) \]

where \( c \) is the side opposite to angle \( C \), and \( a \) and \( b \) are the other two sides.

In your case:

  • Let \( a = 25 \) cm (one side),
  • Let \( b = 19 \) cm (the second side),
  • Let \( c = 24 \) cm (the side opposite \( x \)).

Using the Law of Cosines to solve for \( \cos(x) \):

\[ 24^2 = 25^2 + 19^2 - 2 \cdot 25 \cdot 19 \cdot \cos(x) \]

Calculating \( 24^2 \), \( 25^2 \), and \( 19^2 \):

\[ 576 = 625 + 361 - 950 \cdot \cos(x) \]

Now, simplifying the right side:

\[ 576 = 986 - 950 \cdot \cos(x) \]

Rearranging to isolate \( \cos(x) \):

\[ 950 \cdot \cos(x) = 986 - 576 \] \[ 950 \cdot \cos(x) = 410 \] \[ \cos(x) = \frac{410}{950} \] \[ \cos(x) = 0.4316 \]

Now, we can find \( x \):

\[ x = \cos^{-1}(0.4316) \]

Calculating \( x \):

\[ x \approx 64.4 \text{ degrees} \]

Thus, the measure of angle \( x \) in the triangle is approximately \( 64.4 \) degrees.

The correct response is:

64.4