1. **State the problem:** We need to find the measure of angle 1 ($m \angle 1$) in a triangle where two other angles are given as 37° and 70°. 2. **Recall the triangle angle sum rule:** The sum of the interior angles in any triangle is always 180°. This can be written as: $$m \angle 1 + 37^\circ + 70^\circ = 180^\circ$$ 3. **Set up the equation:** Substitute the known angles: $$m \angle 1 + 37 + 70 = 180$$ 4. **Simplify the sum of known angles:** $$37 + 70 = 107$$ So the equation becomes: $$m \angle 1 + 107 = 180$$ 5. **Solve for $m \angle 1$:** $$m \angle 1 = 180 - 107 = 73$$ 6. **Conclusion:** The measure of angle 1 is 73°. Therefore, $m \angle 1 = 73^\circ$.