Question

quiz 8: solve right, scalene, and obtuse triangle
6 points possible answered: 0/6
question 1
find the length of side ( x ). round to the nearest tenth.
triangle with angles 45°, 75°, and side 17, side ( x ) opposite to 45°?
( x = )
question help: video ebook
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Explanation:

Step1: Find the third angle

The sum of angles in a triangle is \(180^{\circ}\). Let the third angle be \(A\). Then \(A = 180^{\circ}-45^{\circ}-75^{\circ}=60^{\circ}\).

Step2: Apply the Law of Sines

The Law of Sines states that \(\frac{a}{\sin A}=\frac{b}{\sin B}\). Here, if \(x\) is opposite the \(75^{\circ}\) angle and the side of length \(17\) is opposite the \(60^{\circ}\) angle. So \(\frac{x}{\sin75^{\circ}}=\frac{17}{\sin60^{\circ}}\).

Step3: Solve for \(x\)

We know that \(\sin75^{\circ}=\sin(45^{\circ} + 30^{\circ})=\sin45^{\circ}\cos30^{\circ}+\cos45^{\circ}\sin30^{\circ}=\frac{\sqrt{2}}{2}\times\frac{\sqrt{3}}{2}+\frac{\sqrt{2}}{2}\times\frac{1}{2}=\frac{\sqrt{6}+\sqrt{2}}{4}\approx0.966\), and \(\sin60^{\circ}=\frac{\sqrt{3}}{2}\approx0.866\).
Then \(x=\frac{17\times\sin75^{\circ}}{\sin60^{\circ}}\). Substitute the values: \(x=\frac{17\times0.966}{0.866}\approx19.0\).

Answer:

\(19.0\)