TOLONG DIJAWAB YA YANG NOMOR 15,16,18 PAKAI CARANYA

15.)(x+5)+(x+7)+8 = 40 cm
2x + 20 = 40
2x = 40-20
x = 20 :2 = 10cm
t = x+5 = 10 + 5 = 15cm
L= 8x15:2 = 60 cm² (C.)

16.) L= axt
L= (9+5) x 12 : 2
= 14 x 12 : 2 = 84 cm² (B.)

18.) ABC = 180-98 = 82°
ACB = 180 - (82+35)
= 180- 117 = 63° (C.)

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