Question

I can't understand this problem

Answer 1

the answer will be 35 degree you can use external angle Theorem by which the external angle made by two lines of a triangle is equals to the sum of internal angles made by those two lines on third line

Answer 2

here angle zyx = 70°
angle yxz = a

angle yzx = 180° - 70° =110°
now
angle a = 180 - (35 + 110)
= 180- 145
= 35°
So, angle a is 35° .