A is 34 and B is 38, you have to add up all the sides, and for the ones that weren’t given you have to use the things that measure up to it. Like 14 cm and 3 cm in a you needed to double those up since the two other sides were the same length as the ones given. For B you needed to add up 8 and 4 for the top one and subtract seven from six to get the small line thats length wasn’t showed.