1. The problem asks for the measure of angle 1 in a triangle where the other two angles are 53° and 88°. 2. Recall the Triangle Angle Sum Theorem: The sum of the interior angles of a triangle is always 180°. 3. Using the formula: $$m\angle 1 + 53° + 88° = 180°$$ 4. Combine the known angles: $$53° + 88° = 141°$$ 5. Substitute back: $$m\angle 1 + 141° = 180°$$ 6. Solve for $m\angle 1$: $$m\angle 1 = 180° - 141° = 39°$$ 7. Therefore, the measure of angle 1 is 39°.