Question

A triangle has angles that measure 85,46 and (9+4x) degrees,solve for x

Answer 1

x=10

Step-by-step explanation

the sum of the internal angles in a triangle always equals 180,so

Step 1

`\begin{gathered} 85+46+(9+4x)=180 \\ 131+9+4x=180 \\ 140+4x=180\rightarrow Equation(1) \end{gathered}`

Step 2

solve the equation

`\begin{gathered} 140+4x=180 \\ \text{subtract 140 in both sides} \\ 140+4x-140=180-140 \\ 4x=40 \\ \text{divide both sides by 4} \\ (4x)/(4)=(40)/(4) \\ x=10 \end{gathered}`

Step 3

find the missin angle( yellow)

replace x=10

`\begin{gathered} 9+4x \\ 9+4\cdot10 \\ 9+40 \\ 49 \end{gathered}`

so, the yellow angle is 49 degrees

so, the answer is x=10,

I hope this helps you