Question

problem 17: (first taught in lesson 31) find x. after you enter your answer press go. x =

Explanation:

Step1: Recall angle - sum property

The sum of the interior angles of a triangle is $180^{\circ}$. The exterior angle $x$ of the triangle is equal to the sum of the two non - adjacent interior angles.

Step2: Calculate the value of $x$

$x=78 + 45$
$x = 123$

Answer:

$123$