Question

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

Explanation:

Step1: Find adjacent interior angle

The exterior angle and its adjacent interior angle are supplementary, so:
$180^\circ - 133^\circ = 47^\circ$

Step2: Calculate $x$ using triangle sum

The triangle is right-angled, so the sum of non-right angles is $90^\circ$:
$x = 90^\circ - 47^\circ$

Answer:

$43^\circ$