The interior angles of a quadrilateral measure 82°, 97°, 105°, and x°. Find x.

The sum of the interior angles of any quadrilateral is 360°.

Set up the equation:
82° + 97° + 105° + x = 360°

Add the known angles:
284° + x = 360°

Subtract 284° from both sides:
x = 76°

Therefore, the missing angle measures 76°.