Answer:
Apply sine theorem:
1.
c/sinC = a/sinA
=> sinC = sinA x (c/a) = sin70 x 28/24 = 1.096 => Invalid ( 1.096 > 1)
=> C is undefined
=> B is undefined
2.
c/sinC = b/sinB
=> sinB = sinc x (b/c) = sin40 x 34/33 = 0.662
=> B = arcsin(0.662) = 41.47 deg
3.
c/sinC = b/sinB
=> sinB = sinC x (b/c) = sin29 x 26/6 = 2.101 => Invalid ( 2.101 > 1)
=> B is undefined
=> A is undefined
4.
c/sinC = a/sinA
=> sinC = sinA x (c/a) = sin28 x 20/16 = 0.587
=> C = arcsin(0.587) = 35.93 deg
Hope this helps!
:)