Question

find the missing angle of the triangle: - 3y - 2(2y + 4) = - 36

Explanation:

Step1: Apply angle - sum property of triangle

The sum of interior angles of a triangle is 180°. So, $(y - 10)+4y+20 = 180$.

Step2: Combine like - terms

$(y + 4y)+(-10 + 20)=180$, which simplifies to $5y+10 = 180$.

Step3: Isolate the variable term

Subtract 10 from both sides: $5y+10−10 = 180−10$, resulting in $5y = 170$.

Step4: Solve for y

Divide both sides by 5: $\frac{5y}{5}=\frac{170}{5}$, so $y = 34$.

Step5: Find the angles

The first angle is $y - 10=34 - 10 = 24°$, the second angle is $4y=4\times34 = 136°$, and the third is 20°.

Answer:

The angles of the triangle are 24°, 136°, and 20°.