Since you want to use the SAS theorem, you must find sides that are either side of angles BAC and DAE. You have already made use of sides AE and AC, so the other sides you need to choose are AB and AD. The appropriate relationship for similarity is ...
... AD = 2AB
since you want the sides of triangle ADE to be twice then length of those in triangle ABC.
11 1/2+6 4/5 equals? So, you have to make each fraction have the same denominator. So, you would notice that they have in LCD (least common denominator )which is 10. So you're new fractions are 11 5/10+ 6 8/10. 11+6=17. 5/10+8/20=13/10. Which simplified it would be 1 3/10. 17+1 3/10 equals 18 3/10. 18 3/10 -3 3/10 equals 15. 15 is the answer.
I think 20 ft bc microwaves are cool