Question

in the figure below, (mangle2 = 103^{circ}). find (mangle1).

Explanation:

Step1: Identify angle - relationship

$\angle1$ and $\angle2$ are supplementary angles, so $m\angle1 + m\angle2=180^{\circ}$.

Step2: Solve for $m\angle1$

$m\angle1=180^{\circ}-m\angle2$. Substitute $m\angle2 = 103^{\circ}$ into the equation: $m\angle1=180 - 103$.
$m\angle1 = 77^{\circ}$.

Answer:

$77$