Question

solve each triangle abc that exists.
b = 35°00 a = 38.4 b = 30.8
select the correct choice below and, if necessary, fill in the answer boxes within the choice.
○ a. there is only one possible solution for the triangle.
the measurements for the remaining angles a and c and side c are as follows.
a = □°□ c = □°□ c = □
(simplify your answer. round to the nearest (round to the nearest tenth
degree as needed. round to the nearest minute as needed.)
○ b. there are two possible solutions for the triangle.
the measurements for the solution with the longer side c are as follows.
a₁ = □°□ c₁ = □°□ c₁ = □
(simplify your answer. round to the nearest (round to the nearest tenth
degree as needed. round to the nearest minute as needed.)
as needed.)
the measurements for the solution with the shorter side c are as follows.
a₂ = □°□ c₂ = □°□ c₂ = □
(simplify your answer. round to the nearest (round to the nearest tenth
degree as needed. round to the nearest minute as needed.)
as needed.)
○ c. there are no possible solutions for this triangle.

Explanation:

Step1: Convert minutes to degrees

Since \(B = 35^{\circ}00'\), then \(B = 35^{\circ}\)

Step2: Use the Law of Sines

The Law of Sines is \(\frac{a}{\sin A}=\frac{b}{\sin B}=\frac{c}{\sin C}\)
We know \(a = 38.4\), \(b = 30.8\), \(B = 35^{\circ}\)
First, find \(\sin A\): \(\sin A=\frac{a\sin B}{b}\)
Substitute the values: \(\sin A=\frac{38.4\times\sin35^{\circ}}{30.8}\)
\(\sin35^{\circ}\approx0.5736\)
\(\sin A=\frac{38.4\times0.5736}{30.8}\approx\frac{22.02}{30.8}\approx0.715\)
\(A=\sin^{- 1}(0.715)\approx45.7^{\circ}\) or \(A = 180^{\circ}-45.7^{\circ}=134.3^{\circ}\)

Step3: Check for valid triangles

If \(A = 45.7^{\circ}\)
\(C=180^{\circ}-(A + B)=180^{\circ}-(45.7^{\circ}+35^{\circ})=99.3^{\circ}\)
Then find \(c\) using the Law of Sines: \(c=\frac{b\sin C}{\sin B}\)
\(\sin99.3^{\circ}\approx0.986\), \(\sin35^{\circ}\approx0.5736\)
\(c=\frac{30.8\times0.986}{0.5736}\approx\frac{30.37}{0.5736}\approx53.0\)

If \(A = 134.3^{\circ}\)
\(C=180^{\circ}-(134.3^{\circ}+35^{\circ})=10.7^{\circ}\)
\(\sin10.7^{\circ}\approx0.185\)
\(c=\frac{30.8\times0.185}{0.5736}\approx\frac{5.698}{0.5736}\approx9.9\)

Answer:

B. There are two possible solutions for the triangle.
The measurements for the solution with the longer side \(c\) are as follows.
\(A_{1}=46^{\circ}00'\) (since \(45.7^{\circ}\approx46^{\circ}\)), \(C_{1}=99^{\circ}00'\) (since \(99.3^{\circ}\approx99^{\circ}\)), \(c_{1}=53.0\)
The measurements for the solution with the shorter side \(c\) are as follows.
\(A_{2}=134^{\circ}00'\) (since \(134.3^{\circ}\approx134^{\circ}\)), \(C_{2}=11^{\circ}00'\) (since \(10.7^{\circ}\approx11^{\circ}\)), \(c_{2}=9.9\)