Question

Find the value of the unknown angle X.

Answer 1

Answer:

x = $130^{o}$

Step-by-step explanation:

The given figure is a trapezium which is a quadrilateral with four sides.

But,

Sum of angles in a quadrilateral = (n - 2) x 180

where n is the number of sides.

For a quadrilateral, n = 4. So that,

Sum of angles in a quadrilateral = (4 - 2) x 180

                             = 2 x 180

                             = $360^{o}$

The sum of angles in a quadrilateral is $360^{o}$.

Thus,

$158^{o}$ + $51^{o}$ + $x^{o}$ + $21^{o}$ = $360^{o}$

$x^{o}$ + $230^{o}$ = $360^{o}$

$x^{o}$ = $360^{o}$ - $230^{o}$

   = $130^{o}$

The value of x is $130^{o}$.