Помогите решить задачи по геометрии

1) AD = BC + 6
EF = (AD + BC)/2 = ((BC+6) + BC)/2 = (2BC + 6)/2 = 13
2BC + 6 = 26
2BC = 10
BC = 10
AD = BC + 6 = 1- + 6 = 16

2) BB1 и СС1- высоты к AD
< A = < D = 60 град. =>
< ABB1 = < DCC1 = 90 - 60 = 30 град. =>
AB1 = DC1 = AB/2 = 10/2 = 5
B1C1 = BC = 5
AD = AB1 + B1C1 + DC1 = 5 + 5 + 5 = 15
EF = (AD + BC)/2 = (15 + 5)/2 = 10