Answer:
both of these.will be solved by angle sum property which states that sum of all interior angles is 180 degrees
in a
one angle is 30 degrees
other is right angle means 90 degrees
total sum of these angles is 120
total sum of all angle must be 180 degrees
so the third angle is 60 degrees
in b
one angle is 45 degrees
other is a right angle means 90 degrees
total sum of these angles is 135
total sum of all angles must be 180 degrees
so the third angle is 45 degrees
hope this helps
have a good day
thanks for points