Question

angle stv is a straight angle. the measure of angle stw is 100°. the measure of angle wtv is x°. what is the value of x?

Explanation:

Step1: Recall straight - angle property

A straight angle measures 180°. So, $\angle STV=180^{\circ}$.

Step2: Set up an equation

Since $\angle STW + \angle WTV=\angle STV$, and $\angle STW = 100^{\circ}$, $\angle WTV=x^{\circ}$, we have the equation $100 + x=180$.

Step3: Solve for x

Subtract 100 from both sides of the equation: $x=180 - 100$.
$x = 80$.

Answer:

80