Answer :
angle KLM=angleNML=90°
the sum of angles in a triangle is 180°
since: angle2=angle3=x
angle1=angle4=y because
180°-90°-x=180°-90°-x
the sum of angles in a triangle is 180°
since: angle2=angle3=x
angle1=angle4=y because
180°-90°-x=180°-90°-x