a. 6/10 = DF/10 => DF= 6 => ED²= EF²-DF²= 100-36=64 => ED= √64=8
P = 10+6+8 = 24
b. ED/DF= 2, 10/DF=2 => DF=5 ; EF²=ED²+DF²= 100+25=125 => EF=√125=5√5
P= 5+10+5√5=15+5√5=5(3+√5)
c. ED/EF = 7/10 => ED/8=7/10 => ED= 56/10 = 5,6 ;
DF²= EF²-ED²= 64-56/10=584/10= 292/5 => DF= √292/√5
P= 5,6+8+√292/√5 = 13,6+√292/√5
d. ED/DF= 13/10 => 13DF=10ED