Question

find the measure of angle b.
angle b = \boxed{}^\circ

Explanation:

Step1: Recall triangle angle sum

The sum of angles in a triangle is \(180^\circ\).

Step2: Sum known angles

Known angles: \(40^\circ\) and \(120^\circ\). Their sum: \(40 + 120 = 160^\circ\).

Step3: Solve for \(b\)

Subtract from \(180^\circ\): \(b = 180 - 160 = 20^\circ\).

Answer:

\(20\)