Jawabanmu

2014-04-07T17:46:01+07:00
ED = √13^2-5^2 =√169-25 =√144=12 cm, AE = 3/4 DE =3/4 ×12= 9 cm, AD=√ED^2+AE^2 =√12^2+9^2 √144+81 =√225 = 15 cm, kel = 5+14+9+15+15 =58cm
2014-04-07T17:46:23+07:00
Panjang DE^2 = 13^2 - 5^2
DE^2 = 169 - 25 = 144 DE = 12
maka AE = 3/4DE = 3/4 x 12 = 9 cm.
AB = AE + DE = 9 + 12 = 21 cm.
DA^2 = DE^2 + AE^2 = 12^2 + 9^2 = 144 + 81 = 225
DA = 15 cm = BC
keliling = DA + AB + BC + CD = 15 + 21 + 15 + 5 = 56 cm.