Exterior Angle Theorem Math Example 4

Solution

1. 1
   Step 1: Let the exterior angle be $e$ and the remote interior angles be $\alpha$ and $\beta$. By the Exterior Angle Theorem, $e = \alpha + \beta$.
2. 2
   Step 2: Since $\alpha$ and $\beta$ are interior angles of a triangle, both are positive (greater than $0°$).
3. 3
   Step 3: Therefore $e = \alpha + \beta > \alpha$ (since $\beta > 0$) and $e = \alpha + \beta > \beta$ (since $\alpha > 0$).
4. 4
   Step 4: Thus the exterior angle is strictly greater than each remote interior angle.