Answer:
11
Explanation:
A trapezoid is quadrilateral where 2 sides are non parallel and the other two sides are parallel.
An Isosceles Trapezoid consists of non parallel sides having the same angle between the base and top. Here we do not know the other two angles so we have applied the following theorem:
In a trapezoid the sum of the angles on the same side is equal to 180°
So,
9x+7x+4 = 180
⇒16x+4 = 180
⇒16x = 180-4
⇒16x = 176
⇒x = 176/16
⇒x = 11
∴ The value of x is 11