Question

calculate the missing measurement. ∠x = ?°

Explanation:

Step1: Recall angle - sum property

The sum of angles in a triangle is 180°.

Step2: Set up equation

Let the unknown angle be $\angle x$. So, $\angle x+55^{\circ}+45^{\circ}=180^{\circ}$.

Step3: Solve for $\angle x$

$\angle x = 180^{\circ}-(55^{\circ}+45^{\circ})=80^{\circ}$.

Answer:

$80$