Question

if angle ADC is 140 what is the value of x​

Answer 1

See angle ABC is 180-140= 40 degrees as sum of opposite angles of a cyclic quadrilateral is 180
Angle ACB is 90 degrees as it is angle in a semi circle
So angle X is 180-90-40= 50 degrees according to angle sum property

Answer 2

$\: \: step \: by \: step \: explaination \: \div$
We know that,
Angle's on the semi circle is 90°
so,
angle ACB = 90°
Then,
A, b, c, d lying on the circle therefore it is a cyclic quadrilateral.
so,
In Quadrilateral ABCD
=> angle D + angle B = 180° ( sum of opposite angle of a quadrilateral is 180° )
=> 140° + angle B = 180°
=> angle B = 180° - 140°
=> angle B = 40°
Now, In ACB
=> angle A + angle B + angle C = 180° ( sum of all angles of a triangle is 180 )
=> x + 40° + 90° = 180°
=> x + 130° = 180°
=> x = 180° - 130°
=> x = 50°

I hope it will help you

THANK YOU ❤❤