Step-by-step explanation: In the triangle shown, angle <em>x</em> is an exterior angle because it's formed when one side of the triangle is extended. To find the value of <em>x</em>, we use the exterior angle theorem.
This tells us that the measure of an exterior angle of a triangle is equal to the sum of the measures of the remote interior angles. The remote interior angles are all the angles except for <em>x</em>.
So all we need to do is add 47 + 80 and we get a sum of 127.
This means that <em>x</em> is equal to<em> 127°</em>.
