Question

find the measure of angle b. c a 120° b 3 c a 15° b = ?° a = c =

Explanation:

Step1: Recall triangle angle sum property

The sum of the interior angles of a triangle is \(180^\circ\). Let the angles of the triangle be \(\angle A = 15^\circ\), \(\angle C = 120^\circ\), and \(\angle B\) (the angle we need to find).

Step2: Calculate \(\angle B\)

Using the angle sum property, \(\angle A+\angle B+\angle C = 180^\circ\). Substitute the known values: \(15^\circ+\angle B + 120^\circ=180^\circ\).
Simplify the left - hand side: \(135^\circ+\angle B=180^\circ\).
Subtract \(135^\circ\) from both sides: \(\angle B=180^\circ - 135^\circ=45^\circ\).

Answer:

\(45\)