Question

Find the unknown marked angle, in the triangle drawn below.

Answer 1

We know that, Exterior angle of a triangle is always equal to the sum of its two interior opposite angles.
$\Rightarrow {110}^{\circ }=x+{30}^{\circ }$
$\Rightarrow x={110}^{\circ }–{30}^{\circ }\Rightarrow x={80}^{\circ }$