in the fist you have to know: any angle opposite the head is equal in measurement.
so now we know one angle in the triangle it is 82
All corners of the triangle are equal 180
so we have to do this 180-82=98
so we have to collection (4x+8)+(8x-6)=98
12x+2=98
12x=96
x=8
4(8)+8=40
the answer is 40