Question

an angle measures 78° less than the measure of its supplementary angle. what is the measure of each angle?

Explanation:

Step1: Define supplementary angles

Let the angle be $x$. Its supplementary angle is $180 - x$.

Step2: Set up the equation

Given that $x=(180 - x)-78$.

Step3: Solve the equation

Add $x$ to both sides: $x + x=180 - 78$.
$2x = 102$.
Divide both sides by 2: $x=\frac{102}{2}=51$.
The supplementary angle is $180 - 51 = 129$.

Answer:

$51$ and $129$