Answer:
x = 80
Step-by-step explanation:
Thank you for the clear diagram. We don't always get them.
Argument
There are two kinds of angles associated with a triangle
- Interior angles
- Exterior angles
You have both kinds in this question. The interior angles are the ones that make up the triangle itself. The ones you are concerned about are x and 38°.
The other kind is formed by extending one of the sides. In this question, the value of the exterior angle is 118°.
Rule
The two interior angles NOT connected to the given exterior angle are equal (when added) to the exterior angle.
In plain English what that means is
x + 38 = 118
Solution
x + 38 = 118 Subtract 38 from both sides.
x + 38 - 38 = 118 - 38
x = 80
So x = 80
