Question

problem 14: (first taught in lesson 31) find x in this figure. after you enter your answer press go. x =

Explanation:

Step1: Recall angle - sum property of a triangle

The sum of interior angles of a triangle is $180^{\circ}$. Let the third interior angle of the triangle be $y$. So, $y + 50^{\circ}+70^{\circ}=180^{\circ}$.

Step2: Calculate the third interior angle

$y=180^{\circ}-(50^{\circ} + 70^{\circ})=180^{\circ}-120^{\circ}=60^{\circ}$.

Step3: Use the linear - pair property

The angle $x$ and the third interior angle $y$ form a linear - pair. Since the sum of angles in a linear - pair is $180^{\circ}$, then $x + y=180^{\circ}$. Substituting $y = 60^{\circ}$, we get $x=180^{\circ}-60^{\circ}=120^{\circ}$.

Answer:

$120$