Given :
∠ABF = ( 7x + 20 )°
∠FBC=(2x - 5)°
∠ABC= 159°
To Find :
The value of x .
Solution :
Assuming B the center of a circle .
So , all three given angles must be added to 360° .
![(7x+20)+(2x-5)+159=360\\\\9x+15+159=360\\\\x=20.67](https://img.qammunity.org/2021/formulas/mathematics/high-school/upc1ov5u21s7rp4c86u02b4xltfwcexdf0.png)
Therefore , the value of x is 20.67° .
Hence , this is the required solution .