Question

a. which equation can be used to find the value of x?

1. x - 45 = 60
2. x + 45 + 60 = 180
3. x - 45 = 60
4. x + 45 + 60 = 180

Explanation:

Step1: Recall the exterior - angle property of a triangle

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

Step2: Identify non - adjacent interior angles

In the given triangle, the two non - adjacent interior angles to the exterior angle \(x\) are \(45^{\circ}\) and \(40^{\circ}\).
So, \(x=45 + 40\).

Answer:

\(x = 45+40\) (the first option)