its wrong,
it states line ET is tangent to circle A at point T
this means that line NT will be perpendicular to line ET, or that angle NTE is a 90 degree angle
now interior angles of triangles add up to be 180 egrees,
you know TNG is 25, so
90+25+ NET=180
or
180-90-25=NET
and 90+25+50 = 165 which is not 180 which is the reason your answer is incorrect