Question

Find the value of unknown 'x' in the following triangles.

Answer 1

In $△ABC,$

$\angle ABC={50}^o,\angle BCA={60}^o,\angle CAB=x^o$ [ Given ]

We know that, The sum of the angles in a triangle is ${180}^o$

$\therefore$ $\angle ABC+\angle BCA+\angle BCA={180}^o$

$\therefore$ ${50}^o+{60}^o+x^o={180}^o$

$\therefore$ ${110}^o+x={180}^o$

$\therefore$ $x={180}^o-{110}^o$

$\therefore$ $x={70}^o$

$\Rightarrow$ Hence, The value of unknown $x$ is ${70}^o$.