the diagram shows a triangle. what is the value of x? x = □°

Explanation:

Step1: Recall angle - sum property

The sum of interior angles of a triangle is 180°. So, we have the equation $(x + 20)+(x + 20)+3x=180$.

Step2: Combine like - terms

Combining the $x$ terms and the constant terms, we get $(x+x + 3x)+(20 + 20)=180$, which simplifies to $5x+40 = 180$.

Step3: Isolate the variable term

Subtract 40 from both sides of the equation: $5x+40-40=180 - 40$, resulting in $5x=140$.

Step4: Solve for x

Divide both sides of the equation by 5: $\frac{5x}{5}=\frac{140}{5}$, so $x = 28$.

Answer:

$28$