This is the ambiguous case SSA where there are 2 solutions.
The other tutor only gave one of the solutions.  Here
are both solutions:




Substitute what's given:



Take the last two expressions as a equation



Cross-multiply



Divide both sides by 50







The sine is positive in QI and QII, so

B = 75.94844394° and B = 180°-75.94844394 = 104.0515561 

Let's subscript the two possibilities for angle B like this:

B1 = 75.94844394° and B2 = 104.0515561° 

Now we calculate the two possibilities for angle A:

Angle A1 = 180° - Angle B1 - Angle C
Angle A1 = 180° - 75.94844394° - 72°
Angle A1 = 32.05155605°

Angle A2 = 180° - Angle B2 - Angle C
Angle A2 = 180° - 104.0515561°  - 72°
Angle A2 = 3.9484439°

Finally we calculate the two possibilities for side "a":
----------

 and  

Substitute what is now known:

 and  

which shortens to:

 and 

 and 

Divide through by sin(72°)

 and 

 and 

Edwin