tolong pakai cara nya ya no 16-23

19.b.persegi
20.c.15 =karena disitu pangkat dua berarti 15 x 15 = 225
21.L jajargenjang = a x t
                             = 22 x 19
                             = 418 cm3 = d.418
22.L layang2x  = 1/2 x D1 x D2
                        = 1/2 x 23 x 30
                        = 1/2 x 690
                        = 345 =b.345
23.B1 L persegi = s x s
                          = 14 x 14
                          = 196
     B2 L lingkaran = [tex] \pi [/tex] x r2
                             = 22/7 x 7 x 7
                             = 22 x 7
                             =154

L = B1 -B2
   = 196 - 154
   = 42 = C. 42

19.persegi
Maaf cuman bisa jawab itu....maaf ya