150k views
2 votes
Determine the value of y given that the lengths of the sides of a triangle are 11 cm, 8 cm, and 3 cm. Submit your answer correct to 1 decimal place.

1 Answer

6 votes

Final Answer:

The value of
\( y \) in the given triangle with side lengths 11 cm, 8 cm, and 3 cm is approximately
\( y = 104.1 \) cm, rounded to one decimal place.

Step-by-step explanation:

To determine the value of
\( y \), we can use the Law of Cosines for triangles. The Law of Cosines relates the lengths of the sides of a triangle to the cosine of one of its angles. For a triangle with sides of lengths
\( a \),
\( b \), and
\( c \) and an angle
\( C \) opposite side
\( c \), the Law of Cosines is given by the formula:


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

In this case, the sides of the triangle are 11 cm, 8 cm, and 3 cm. Let's denote
\( y \) as the angle opposite the side of length 3 cm. Plugging in the values, we get:


\[ 3^2 = 11^2 + 8^2 - 2 \cdot 11 \cdot 8 \cos(y) \]

Solving for
\( \cos(y) \), we find
\( \cos(y) = (1)/(16) \). Taking the inverse cosine, we get
\( y \approx 104.1^\circ \).

Therefore, the value of
\( y \) is approximately
\( y = 104.1 \) cm, rounded to one decimal place. This represents the measure of the angle opposite the side of length 3 cm in the given triangle. The Law of Cosines is a powerful tool for solving triangles when the lengths of the sides are known, providing a way to find angles and complete the triangle's geometric information.

User Wholeman
by
7.7k points