Math Problem Statement

Solve each triangle ABC that exists. Aequals44.5degrees     aequals8.2 m      bequals10.7 m Question content area bottom Part 1 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 B and C and side c are as follows. Bequals    enter your response heredegrees ​(Round to the nearest tenth as​ needed.) Cequals    enter your response heredegrees ​(Round to the nearest tenth as​ needed.) cequals    enter your response here ​(Round to the nearest tenth as​ needed.) B. There are two possible solutions for the triangle. The measurements for the solution with the longer side c are as follows. Upper B 1equals    enter your response heredegrees ​(Round to the nearest tenth as​ needed.) Upper C 1equals    enter your response heredegrees ​(Round to the nearest tenth as​ needed.) c 1equals    enter your response here ​(Round to the nearest tenth as​ needed.) The measurements for the solution with the shorter side c are as follows. Upper B 2equals    enter your response heredegrees ​(Round to the nearest tenth as​ needed.) Upper C 2equals    enter your response heredegrees ​(Round to the nearest tenth as​ needed.) c 2equals    enter your response here ​(Round to the nearest tenth as​ needed.) C. There are no possible solutions for this triangle.

Solution

This problem involves solving a triangle given two sides (a=8.2ma = 8.2 \, \text{m}, b=10.7mb = 10.7 \, \text{m}) and one angle (A=44.5A = 44.5^\circ). We can solve this triangle using the Law of Sines, as it relates angles to their opposite sides. However, we must first check whether there is one solution, two solutions, or no solution. This is known as the ambiguous case (SSA case) in trigonometry.

Step 1: Use the Law of Sines

The Law of Sines is expressed as: asinA=bsinB=csinC\frac{a}{\sin A} = \frac{b}{\sin B} = \frac{c}{\sin C} We can solve for angle BB first. Rewriting the Law of Sines for BB: sinB=bsinAa\sin B = \frac{b \sin A}{a} Substitute the known values: sinB=10.7sin44.58.2\sin B = \frac{10.7 \cdot \sin 44.5^\circ}{8.2}

Step 2: Calculate sinB\sin B

First, calculate sin44.5\sin 44.5^\circ, and then solve for sinB\sin B: sin44.50.6986\sin 44.5^\circ \approx 0.6986 sinB=10.70.69868.20.9114\sin B = \frac{10.7 \cdot 0.6986}{8.2} \approx 0.9114

Step 3: Check for possible solutions

Since sinB0.9114\sin B \approx 0.9114, and the sine of an angle can only be between -1 and 1, this indicates that angle BB exists.

Now, we find BB using the inverse sine function: B=sin1(0.9114)65.6B = \sin^{-1}(0.9114) \approx 65.6^\circ

Since sinB\sin B is positive, there are two possible solutions for BB because sin(θ)=sin(180θ)\sin(\theta) = \sin(180^\circ - \theta). Thus:

  • The first possible value of BB is 65.665.6^\circ.
  • The second possible value of BB is 18065.6=114.4180^\circ - 65.6^\circ = 114.4^\circ.

Step 4: Check the sum of angles

If B=65.6B = 65.6^\circ, then angle CC can be found by using the fact that the sum of angles in a triangle is 180180^\circ: C=180AB=18044.565.6=69.9C = 180^\circ - A - B = 180^\circ - 44.5^\circ - 65.6^\circ = 69.9^\circ

If B=114.4B = 114.4^\circ, then: C=180AB=18044.5114.4=21.1C = 180^\circ - A - B = 180^\circ - 44.5^\circ - 114.4^\circ = 21.1^\circ

Step 5: Solve for side cc

Using the Law of Sines again: csinC=asinA\frac{c}{\sin C} = \frac{a}{\sin A} Thus: c=asinCsinAc = \frac{a \cdot \sin C}{\sin A}

For the first case, where C=69.9C = 69.9^\circ: c=8.2sin69.9sin44.58.20.93620.698610.98mc = \frac{8.2 \cdot \sin 69.9^\circ}{\sin 44.5^\circ} \approx \frac{8.2 \cdot 0.9362}{0.6986} \approx 10.98 \, \text{m}

For the second case, where C=21.1C = 21.1^\circ: c=8.2sin21.1sin44.58.20.35950.69864.22mc = \frac{8.2 \cdot \sin 21.1^\circ}{\sin 44.5^\circ} \approx \frac{8.2 \cdot 0.3595}{0.6986} \approx 4.22 \, \text{m}

Final Answer:

There are two possible solutions for the triangle:

  1. First solution:

    • B=65.6B = 65.6^\circ
    • C=69.9C = 69.9^\circ
    • c=11.0mc = 11.0 \, \text{m}
  2. Second solution:

    • B=114.4B = 114.4^\circ
    • C=21.1C = 21.1^\circ
    • c=4.2mc = 4.2 \, \text{m}

Would you like further details or clarifications?

Related Questions:

  1. What are the conditions for having two solutions in a triangle with SSA?
  2. How does the Law of Sines apply to ambiguous cases in trigonometry?
  3. Can there ever be no solution for a triangle with SSA? Under what conditions?
  4. How do you use the Law of Cosines to solve triangles?
  5. What are the possible ranges for the sine of an angle in a triangle?

Tip:

When solving SSA triangles, always check the possibility of two solutions by considering both θ\theta and 180θ180^\circ - \theta.

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Math Problem Analysis

Mathematical Concepts

Trigonometry
Law of Sines
Ambiguous Case (SSA)

Formulas

Law of Sines: a/sin(A) = b/sin(B) = c/sin(C)
Sum of angles in a triangle: A + B + C = 180 degrees
Calculation of side using Law of Sines: c = (a * sin(C)) / sin(A)

Theorems

Law of Sines
Ambiguous Case for SSA in Triangles

Suitable Grade Level

Grades 10-12