Question

find the measure of the third exterior angle in this triangle. 120° 155° ?°

Explanation:

Step1: Recall exterior - angle sum property

The sum of the exterior angles of any triangle is 360°.

Step2: Set up an equation

Let the third exterior - angle be \(x\). We know two exterior angles are 120° and 155°. So, \(x + 120+155=360\).

Step3: Solve for \(x\)

\(x=360-(120 + 155)\)
\(x=360 - 275\)
\(x = 85\)

Answer:

85°