Question

what is m∠1? 74° 1 123° m∠1 = □°

Explanation:

Step1: Find the adjacent interior angle

The angle adjacent to \(123^\circ\) on a straight line sums to \(180^\circ\). So the interior angle is \(180 - 123 = 57^\circ\).

Step2: Use triangle angle sum

The sum of angles in a triangle is \(180^\circ\). Let \(m\angle1 = x\). Then \(74 + 57 + x = 180\).

Step3: Solve for \(x\)

\(131 + x = 180\), so \(x = 180 - 131 = 49\).

Answer:

\(49\)