Question

what is $mangle1$?
$mangle1=square^{circ}$

Explanation:

Step1: Use the exterior angle theorem

The exterior angle theorem states that an exterior angle of a triangle is equal to the sum of the two non - adjacent interior angles.

Step2: Calculate \(m\angle1\)

Given the two non - adjacent interior angles \(60^{\circ}\) and \(69^{\circ}\), we find \(m\angle1\) by adding them. So, \(m\angle1=60 + 69\).

$$m\angle1=129$$

Answer:

\(129\)