tolong yaa. 19-20 :)

20.
Luas limas = L alas + jmlh luas sisi tegak
                   = 32 x 18 + 4 x 1/2 . alas . t
                   = 576 + 4 x 1/2 . 18 . 20
                 = 576 + 4 x 180
                 = 576 + 720
               = 1296 ( A )


tinggi segitiga miskn dengan x :

x^2 = 16^2 + 12^2
     = 256 + 144
     = 400
x    = 20

Nomor 19
Luas Alas (Trapesium ) :
= 1/2 (AE + BF) . AB
= 1/2 (8 + 5)cm . 4 cm
= 1/2 . 13 . 4
= 26 cm²

EF = √[(AE - BF)² + AB²]
EF = √[(8 - 5)² + 4²]
EF = √(3² + 4²)
EF = √(9 + 16)
EF = √25
EF = 5 cm

Keliling Alas (Trapesium) :
= AE + BF + AB + EF
= 8 cm + 5 cm + 4 cm + 5 cm
= 22 cm

Jadi,
Luas Permukaan Prisma :
= 2. L alas + K alas . T prisma
= 2 x 26 cm² + 22 cm . BC
= 52 + 22 cm . 6 cm
= 52 + 132
= 184 cm² (C)