1. ## Finding unknown angle

i want to know how to solve this question to find the x in it.And with explanation as i don't know how to solve it.

2. Is that a parallelogram with its lower left corner "cut off"? If so, then imagine that you have this corner. It would form a triangle, with two of angles being are supplemental angles of 3x and 132°. The 3rd would have be 2x.

The sum of these angles is 180°, so the equation is
$\displaystyle (180^{\circ} - 3x) + 48° + 2x = 180^{\circ}$.

Solve for x.

3. where has 48 come from ?

4. Originally Posted by haftakhan
where has 48 come from ?
It's the supplementary angle for the 132°, one of the three angles in the "torn corner" of the parallelogram.

5. Can u explain it in detail as i cant understand it

6. Look at the attached diagram:

I've added a "corner" to the parallelogram in your original drawing, and then I enlarged the corner. I'm assuming that this "corner" forms a triangle. The sum of angles a, b, and 2x has to equal 180°.

Angle a is the supplement of 3x, so $\displaystyle a = 180^{\circ} - 3x$. Angle b is the supplement of 132°, so $\displaystyle b = 180^{\circ} - 132^{\circ} = 48^{\circ}$. Therefore, the sum of the angles in this triangle is
$\displaystyle (180^{\circ} - 3x) + 48° + 2x = 180^{\circ}$.