Question

1. (x + 90)° 4x°

Explanation:

Step1: Set up equation using vertical - angle property

Vertical angles are equal. So, $x + 90=4x$.

Step2: Solve for x

Subtract $x$ from both sides: $90 = 4x−x$.
$90 = 3x$.
Then divide both sides by 3: $x=\frac{90}{3}=30$.

Answer:

$x = 30$