Question

use the triangle shown. if m∠1 = 98° and m∠2 = 19°, what is m∠3? m∠3 =

Explanation:

Step1: Recall angle - sum property of a triangle

The sum of the interior angles of a triangle is 180°. Angle 1 is an exterior angle. The exterior - angle of a triangle is equal to the sum of the two non - adjacent interior angles. So, \(m\angle1=m\angle2 + m\angle3\).

Step2: Solve for \(m\angle3\)

We can rewrite the equation as \(m\angle3=m\angle1 - m\angle2\). Substitute \(m\angle1 = 98^{\circ}\) and \(m\angle2 = 19^{\circ}\) into the equation. Then \(m\angle3=98^{\circ}-19^{\circ}\).

Answer:

\(79\)