160k views
4 votes
Solving right triangle find the missing side. round to the nearest tenth number 15

Solving right triangle find the missing side. round to the nearest tenth number 15-example-1

1 Answer

2 votes

To solve the triangle we are going to first find the measures of all the angles:


\begin{gathered} A=47\text{\degree} \\ B=90\text{\degree}\Rightarrow\text{ Because is a right triangle} \\ A+B+C=180\text{\degree} \\ \text{Because the sum of the internal angles of a triangle is 180 degrees} \\ 47\text{\degree}+90\text{\degree}+C=180\text{\degree} \\ 137\text{\degree}+C=180\text{\degree} \\ \text{ Subtract 137\degree from both sides of the equation} \\ 137\text{\degree}+C-137\text{\degree}=180\text{\degree}-137\text{\degree} \\ C=43\text{\degree} \end{gathered}

Now to find the measures of the sides you can use trigonometric ratios because it is a right triangle:

Side a: you can use the trigonometric ratio tan(θ)


\tan (\theta)=\frac{\text{ opposite side}}{\text{adjacent side}}
\begin{gathered} \tan (47\text{\degree})=(a)/(28) \\ \text{ Multiply by 28 from both sides of the equation} \\ \tan (47\text{\degree})\cdot28=(a)/(28)\cdot28 \\ 30=a \end{gathered}

Side b or side x: you can use the trigonometric ratio cos(θ)


\cos (\theta)=\frac{\text{adjacent side}}{\text{hypotenuse}}
\begin{gathered} \cos (47\text{\degree})=(28)/(b) \\ \text{ Multiply by b from both sides of the equation} \\ \cos (47\text{\degree})\cdot b=(28)/(b)\cdot b \\ \cos (47\text{\degree})\cdot b=28 \\ \text{ Divide by cos(47\degree) from both sides of the equation} \\ \frac{\cos (47\text{\degree})\cdot b}{\cos (47\text{\degree})}=\frac{28}{\cos (47\text{\degree})} \\ b=\frac{28}{\cos(47\text{\degree})} \\ b=41.1 \end{gathered}

Therefore, when solving the triangle you have


\begin{gathered} A=47\text{\degree} \\ B=90\text{\degree} \\ C=43\text{\degree} \\ a=30 \\ b=41.1 \\ c=28 \end{gathered}

and the missing side is


\begin{gathered} b=x \\ x=41.1 \end{gathered}

Solving right triangle find the missing side. round to the nearest tenth number 15-example-1
Solving right triangle find the missing side. round to the nearest tenth number 15-example-2
User Surfasb
by
8.6k points

No related questions found

Welcome to QAmmunity.org, where you can ask questions and receive answers from other members of our community.

9.4m questions

12.2m answers

Categories