Alex's pythogorean scribe

OK. so for my scribe, I decided to do question 14 on page 113 so here it is.
14).the question for this is find the missing side length of each triangle.

a)c+b=d-each of these letters are supposed to be squared
12m+5m=d-each of these letters are supposed to be squared
(12mx12m)+(5mx5m)=d-the d is supposed to be squared
144+25=d-the d is supposed to be squared
169=d-the d is supposed to be squared
169=d-the d is supposed to be squared and their should be a square root over the 169 and d
13=d

b)w-t=v-each of these letters are supposed to be squared
15cm-9cm=v-each of these letters are supposed to be squared
(15cmx15cm)-(9cmx9cm)=v-the v is supposed to be squared
225-81=v-the v is supposed to be squared
144=v-the v is supposed to be squared
144=v-the v is supposed to be squared and their should be a square root over the 144 and v
12=v

So A's side length is 13m and B's side length is 12cm.