You could have a breeding trap, but if you have alot in there in a few weeks it will be too small.
If you want the fry to live you either need a smaller tank, like a 30ltr or something or give them away.
As evilchild said, the Angel will more than likely eat them all. The guppys will also have a peck at them too.
If you have plenty of small hiding places some might survive.
Bear in mind a stong filter will suck them up, so you might need them in a smaller tank with a small fry filter, also that fry need to be fed about 3 - 5 times a day small amounts.