Question

value of x.
73°
128°
x =

Explanation:

Step1: Recall exterior - angle property

The exterior - angle of a triangle is equal to the sum of the two non - adjacent interior angles.
Let the triangle have interior angles \(x\), \(73^{\circ}\), and the third angle. The exterior angle is \(128^{\circ}\).
So, \(x + 73^{\circ}=128^{\circ}\).

Step2: Solve for \(x\)

Subtract \(73^{\circ}\) from both sides of the equation: \(x=128^{\circ}-73^{\circ}\).

Answer:

\(x = 55^{\circ}\)