Question

problem 20: (first taught in lesson 42) find ( mangle nrt ). after you enter your answer press go. ( mangle nrt= )

Explanation:

Step1: Identify the triangle type

Since \( SR = SN \), \(\triangle SRN\) is an isosceles triangle. So, \(\angle S=\angle N = 71^{\circ}\).

Step2: Use the exterior - angle theorem

The exterior - angle theorem states that the measure of an exterior angle of a triangle is equal to the sum of the measures of the two non - adjacent interior angles. For \(\triangle SRN\) and exterior angle \(\angle NRT\), \(m\angle NRT=\angle S+\angle N\).
Since \(\angle S = \angle N=71^{\circ}\), then \(m\angle NRT=71^{\circ}+71^{\circ}\).

Answer:

\(142^{\circ}\)