Question

a side of the triangle below has been extended to form an exterior angle of 133°. find the value of x.

Explanation:

Step1: Identify interior-exterior angle pair

The exterior angle and adjacent interior angle are supplementary, so the adjacent interior angle is $180^\circ - 139^\circ = 41^\circ$.

Step2: Use triangle angle sum property

The sum of angles in a triangle is $180^\circ$. Let the unknown angle be $x$, so $x + 90^\circ + 41^\circ = 180^\circ$.

Step3: Solve for $x$

Calculate $x = 180^\circ - 90^\circ - 41^\circ = 49^\circ$.

Answer:

$49$