If a° > 90°, find the range of values that the expression y - x must be.

Question

a°=180-y°+x°

 a is an exterior angle of a triangle with the two remote interior angles being 180-y and x.

Answer 1

a>90 since it's exterior; a>180

180-y-x=z

y-x=180-2y-x

x=30, y=60, z=90=

Answer 2

180° - y + x > 90°

90° - y + x > 0°

90° > y - x