tolong jawab lima soal ini ya kakak pliss bangett♥

1. 78 = 1/2.a.12            c = √13²+12²  = 17,69
    78 = 6a                      maka, K = 12 + 13 + 17,69 = 42,69 cm             
    a = 13 cm

2. L = p.l
    48 cm² = 8.(4x-2)
    48 = 32x-16
    48+16 = 32x
    64 = 32x
    x = 2

3. L = 1/2.d1.d2
    125 = 1/2.10/d2
    125 = 5.d2
    d2 = 25 cm

4. L = 1/2(a+b)t
       = 1/2.(14+18).12
       = 22.6 = 132 m² x Rp 80.000 = Rp 10.560.000

5. L = a.t
   338 = 2t.t
   338 = 2t²
   t² = 169
   t = 13
maka, tingginya 13 m dan panjang alasnya 13x2= 26 m