Question

1. find the missing angle.

Explanation:

Step1: Identify the shape

The shape is a parallelogram. In a parallelogram, adjacent - angles are supplementary.

Step2: Set up the equation

Let the missing angle be $x$. We know that $x + 105^{\circ}=180^{\circ}$ (since adjacent angles in a parallelogram add up to $180^{\circ}$).

Step3: Solve for the missing angle

$x=180^{\circ}- 105^{\circ}=75^{\circ}$

Answer:

$75$